A/N: He knew...He knew all this time...but pretended not too...

Mammon: LUCIFER!!!!

The House Of Lamentation went quiet the moment everyone heard Mammon's angry scream directed at the eldest brother.

As much as the brothers did wanted Mammon to come home. But not like this.

Levi held onto his goldfish Henry's bowl out of paranoia. Even if Mammon's anger isn't directed at him.  It still scary to him when Mammon is angry.

Satan scowled wondering what Lucifer did now to piss Mammon off. Hasn't he ruin things out of spite enough already?

Asmo looked scared wondering what was going to happen.

Beel, even though Mammon was the one telling, looked ready to defend him just in case Lucifer does something he'll regret.

Belphie quietly hid behind his twin. As much as he wants to see Lucifer get told off. But by Mammon of all people, it did make him worry about what negative effects were going to happen now.

Lucifer: What is it, Mammon? Have you decided to come to your senses and return home?

Oh the audacity this bitch has, sometimes...

Mammon:....You knew...

Mammon spoke quietly but his brothers used their senses to sharpen their hearing.

Satan: Lucifer knew what? 

Satan brought up the conversation to let Mammon continue.

Mammon: He knew...He knew it was my birthday that day...all this time...He knew!!!

The brothers all gasped before glaring at the first eldest!

Lucifer:...How did you...

Mammon pulled out the proof. Showing the invitation that was found in Lucifer's room.

Mammon: A little birdie and demon familiar told me everything....

Lucifer swore underneath his breath. How could he forget about Mammon's crow familiars and Lil D No. 2? He was the one who assigned Mammon to use them to watch over Devildom for information. He wanted to kick himself at how stupid he had become but his pride wouldn't allow it. No matter what excuse he could come up with. It didn't matter. He was caught.

Lucifer: Yes...I knew....

Hearing the words flew out of his mouth, made all his other brothers exploded in rage. He knew it was Mammon's Birthday. He knew all this time!!!

Levi: YOU KNEW??!!

Asmo: WHAT THE HECK, LUCIFER?!!

Satan: HOW CAN YOU KEEP THIS FROM US?!!

Beel: WHY DIDN'T YOU TELL US?!!

Belphie: Die...Die...Just Die Lucifer...

The brothers continued to complain and for once, Lucifer didn't use any pride or authority to shut them up. He was too busy staring at Mammon.

Lucifer: I did it for you. Mammon.

Mammon:....Are you serious???

Lucifer: I did that so you could become stronger so you wouldn't have to rely on no one. You need to understand that you're one of the strongest demons here, Mammon. It wouldn't do Lord Diavolo any good if you so much as falter and ruin his reputation. You need to stop acting selfish, childish, and clingy. It's unbecoming of a demon lord.

Seriously. That's his excuse?! It got Mammon's blood boiling.

Lucifer: One day you'll understand-?!

Mammon: Go Fuck Yourself.

Lucifer: Excuse Me-?!

Lucifer cut himself upon seeing the emotionless look in Mammon's face.

Uh-Oh...

No...Not Again...

Mammon: You knew...and you forgot my birthday on purpose...Just so you can go please Diavolo...by hurting me? See Luci. You'll just proved my point  You haven't changed at all.

Lucifer:.....

Silence was all you could hear as the brothers all looked guilty to the side as Mammon continues to stare at Lucifer, who for once, looked very uncomfortable. It was so silent, you can hear a pin drop or the slightest chance of hearing sounds could set the Second Eldest off into a fury again..

Mammon: Selfish? Childish? Clingy? Scumbag? Burden? That's all I ever hear from ya guys.

Brothers:....

Mammon: I'll never be good enough for you...Will I?

Lucifer:....

Mammon: All I ever wanted...was your praise, Lucifer and love from our brothers...but all I ever get are butt monkey name-calling, insults, and disappointment especially when it comes to pleasing Diavolo.

Lucifer:....Mammon, I can assure you that-!

Mammon: SPARE ME YOUR EMPTY WORDS.

SILENCE.

Mammon: No matter how much I try...I even tried to not indulge in my sin. I've tried not to take. To steal. To borrow money. But even I know I have my limits. Which is something you don't understand or even want too...Because the first thing outta your mouths is wondering if I've done something wrong!

...

Mammon: How long...are ya going to continue acting this way? Like you had never harmed me before...Like the pity party I had weeks ago wasn't enough for you?!!

Lucifer: I have no idea what you're talking about.

Mammon: You don't even see me as a person, Lucifer! You only see me as a tool. I'm done being your punching bag! That's not my job! My job was to take care of our brothers or help give ya information all around Devildom when you're too busy with work and taking care of everything for Diavolo!

Lucifer:....

Mammon: But I can't do that when you guys accuse me of every little thing that goes bad!!!! Especially when y'all bashing me for my sin! When something goes wrong. I'm the only one getting blamed!

Lucifer: Mammon...

Mammon: When the others indulge in their sins. You barely do a thing.

Lucifer: That's different, Mammon-!

Mammon: Shut up! I'm talking here, Lucifer! YOU WILL LISTEN TO ME!!! When it comes to me, you attack me! You guys gang up on me and treat me like crap! I'm sick and tried of it! I'M DONE!!!

....

Mammon: You haven't changed at all...You don't even feel sorry. You're just feeling guilty for your actions but tries to save face because of your pride!...

Lucifer:...

Then he turned to his brothers who all looked pale and looked sick to their stomachs.

Mammon: You guys are not any better either. Remembering your insults. Your taunts. Your jeers. Your laughs. Your threats. Your wishes for death on me. Who do you guys think you are?! I am your older brother! Not just Satan, I basically raised all of you when Lucifer didn't bother too! I'm superior to y'all in more ways than one! Whose to say I do forgive you guys and come back! Y'all just go back to insulting me!!!

Levi: No Mammon! We wouldn't do that!

Asmo: We promised we wouldn't!

Mammon: Yeah right! Remember when I ran away and didn't come back for almost a week! Days prior for one insults too many?!

Levi: Well...We...I...

Satan: Just save it, Leviathan. We fucked up. This entire family is already fucked up. Just stop pretending nothing is wrong. We screwed up.

Brothers:....

Mammon: .Demon or not. I can't keep living like this...I always try to refrain from getting mad! I'm not taking your bullshit any longer! So guess what...When you guys apologized to me after the party. I actually thought about forgiving you guys...Well now...I don't.

The demon brothers gasped in horror. Does this mean...They lost their chance to reconcile with Mammon?! No...No! This can't be!

Beel: Mams...No...

Belphie: *Sad and Scared* This can't be happening...This can't be happening...

The younger brothers were all closed to tears again. They were going to lose Mammon once more...! This time...probably forever..

And it would be their faults...but mostly Lucifer's...

Mammon: This will not go on any longer either, Lucifer!!! I've had it! I've had enough of beating around the bush! I thought you actually cared...but I guess I was wrong!!!

....

Mammon: Basically...telling me not to sin is stupid, Lucifer. We're demons. We fell from Heaven after that war and losing Lilith! We all have sinned with no regard for those around us!

True. Demons had sinned. But so have humans and angels. People were just under the mindset that it meant when demons do it. They didn’t harbor any good within their hearts.

Hypocrital. If that the case, why murder someone in cold blood?

That they did nothing more than fall deeper into sin when sin was a disgusting, horrible creature. How could someone want to indulge in the harsh and cruel? It was completely against him and his morals to do so.

For Luke's case...well, it might just be the thing angels will never understand about demons and vice-versa. Still, it wasn’t right for him to believe sin made them cruel, unloving monsters when some had gentle hands.

Which is why he hate demons. But Mammon and Barbatos were giving him better opinions about them which is why he likes them. Because despite being seen as demons - cruel creatures - They did nothing but love and care.

So telling a demon not to sin or indulge in it... Especially if you're the Avatar of that sin is like taking away someone's livelihood.

Mammon: I am not happy. I'm not having fun! I am not going to pretend anymore that nothing is wrong while you treat me this way! Being in the same room as any of ya feels suffocating, I always want to bury myself alive, hide myself again where none of you can find me...I don't want to eat! I don't want to drink! I don't want to sleep!...I don't even want to have another birthday because I know if I do! You'll just forget!

The brothers all flinched. All they can do was stare. Once again, they don't know how to comfort Mammon.

Mammon: What you just did Lucifer...was an act of betrayal! I can never..truly...forgive you.

Just like that, everything comes crashing down on Lucifer...like all of the sacrifices he made to built and protect for his brothers comes crumbling down right in front of him.

Lucifer:......

Mammon: *Mocking* Is it your pride, Luci? Does it hurt your pride to wish your 'brother' a happy birthday? Or is it because my greed is stronger than your pride? Are ya jealous? Here I thought Leviathan was the only Avatar of Envy.  So instead you tell me to go kill myself despite promising to protect me? Well...ya broke it...again.

Lucifer:........(No...No...No...)

Mammon: Ya broke that silly stupid ass promise from every day for hundreds of years, through every last fucking punishment you served, every time you made me cry, every insult you didn't defend me from the others!

Brothers:.....

Mammon: Because it's obvious that just like Michael...I don't mean a damn thing to ya. Yer an demon version of him! My suffering just amuses your pride! I'm just a fucking tool. A scumbag! A punching bag that's so fucking miserable whose purpose only exists to be punished to satisfy your sadistic cardinal pride!!! I'M FUCKING FED UP AND TIRED OF IT, LUCIFER!!! I'M FUCKING DONE WITH YER SELF-CENTERED ARROGANT BULLSHIT!!!

Screw his pride...It had ruined everything once again...He couldn't take this...

Lucifer: Mammon...I...I...

Mammon: *ANGRY* What?

He stood there waiting for Lucifer's response. Might as well enlighten him. He's already had enough of the empty promises and apologies.

Lucifer:....I'm.....Sorry....

Mammon:....

He didn't sound sorry...something just snapped inside the second eldest.

Suddenly, Mammon let out a chuckle...before be started laughing...to the point where he had reach insanity once again.

Mammon: *INSANE* Oh! You heard that? He's sorry! He's sorry! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY!SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY! SORRY!!!

Mammon then snapped once again and went into his demon form then attacks Lucifer while letting an anguish scream!!!

The House Of Lamentation flew into chaos once again.

But this time, no one stopped him.

*PUNCH*

Mammon: YOU LIED TO ME!!!

Lucifer: I'm sorry...

*CRASH*

Mammon: YOU HURT ME! YOU DESTROYED ME! YOU RUINED MY PARTY!!! YOU BROKEN EVERYTHING!!!

*POW*

Lucifer: I'm sorry...

Mammon: HOW MUCH LONGER ARE YOU GOING TO TAKE EVERYTHING FROM ME!!!!

Lucifer: I'm sorry...

No matter how many times he apologized. Mammon won't forgive him.

Mammon: FIGHT ME! FIGHT ME YOU BASTARD! I HATE YOU! I HATE YOU!!! I HATE YOU SO MUCH!!!

No matter how much he punched, rip, tear, shred, and bite at Lucifer. The pride demon wouldn't fight him.

None of the other brothers even had to heart to interfere or stop him as they watched him ripped Lucifer into pieces as blood spread everywhere from each punch, bite, and tear. They shuddered hearing every sound echoed through their ears.

It was a horrible scene.

After like an hour or so. Mammon finally calmed down before breaking down once again crying on Lucifer's battered and bloody chest that was covered in cuts and scars made by him.

Mammon: *Sobbing* I hate you...I hate you...I hate you...

Lucifer:.......Mammon.

Lucifer, weakly, tried to stop the tears from flowing down the younger's face but Mammon pulled away. He got off of him and backed away from the first eldest.

Mammon: I'm done...I can't take it anymore. You just proved that I can't trust you or any one of our brothers...You don't even see me as a brother!!! JUST STAY AWAY FROM ME!!! ALL OF YOU!!!

Levi: No!

Satan: MAMMY!

Beel: DON'T LEAVE!!!

They all tried to reach him desperately but this provoked him.

Mammon: STAY AWAY!!!!!!

An visible orange force that came pushed the brothers all back away from the second eldest.

Mammon: DON'T COME NEAR! DON'T TALK TO ME! DON'T TOUCH ME! I CAN'T TRUST YOU GUYS! STAY AWAY FROM ME!!!! FOREVER!!!!!!!

*BAM*

Like he did last time, Mammon ran away...for the third and final time. He broke another hole through the wall and flees the HOL. Ignoring all this brothers cries for him.

Brothers: *Crying* MAMMON!!!

Satan: THIS IS ALL YOUR FAULT!!!!

Now it was Satan's turn to attack Lucifer in fit of rage. He charged at Lucifer in his demon form and physically assaulted him with his WRATH.

The other brothers continued crying and pleading for Mammon to come back. Despite getting beat up, Lucifer let's the bloody tears roll down his face...

Mammon was gone and now...Now their family was ruined once again...

Just like...how they lost Lilith...All of this...was the fault of the first eldest.

Lucifer: *Despair*...Mammon...

They lost Mammon...He's not coming back...All it took was a pity party for the second eldest to reach his breaking point.