Lightning probably got blackmail pictures from Mephisto of the ExWire boys Cross dressing for the 7 mysteries missions. He showed it to Rin and Rin couldn't look at Ryuji for a while without laughing.

Rin made a ridiculous amount of flirty jokes about it just to get on Ryuji’s nerves and make his face turn red.

“So, am I ever gonna get to see those skull-crushing thighs in a skirt?” The half-demon smirked. His boyfriend's face immediately turned bright red. "No! And how did you even find out about that?!" The teen snapped. Rin pouted. "Not telling! But I thought it was a nice thing to do for the girls." Rin answered offhandedly. "I'm glad I'm not an ExWire now. That would've been really embarrassing." Rin snickered. "Oi, it was for the mission. Do what you gotta do!" Ryuji was not enjoying being teased.

"Relax babe, nothing can surprise me at this point. I grew up in America. I've seen a lot of weird shit." Rin reminded him. "Oh really? Have you ever seen guys crossdress in America?" Ryuji challenged. The shorter teen nodded. "Yup. There were some guys that wore girls' clothes to school once to protest the dress codes. If girls could wear whatever they wanted, so could guys." He shrugged.

"Hey, if it makes you feel any better, I once lost a bet to Dad and wore crop tops and heels to school for an entire month. My wardrobe is half crop tops now." Rin told him. "And did you get made fun of?" Ryuji questioned. "Nah. I mean, yeah, a few cliche jocks called me a Fairy, but most of the other students thought I was awesome for being so forward." Rin shrugged. "America is seriously crazy." Ryuji shook his head in disbelief. "It's called freedom. Gay marriage is legal in San Fransisco. Pride month is June. Gay bars are everywhere." Rin listed off.

"Yeah, well, this is Japan and here, people don't approve of that stuff. So no, I'm not gonna wear a skirt for you." Ryuji ended the discussion, turning to finish his studying while Rin pouted at him.

§~•~§~•~§

Sometimes Rin will use it an argument. 

“When are you gonna stop getting into my stuff?!”

“When are you gonna wear a skirt for me?” 

"You've crossdressed before, why don't you wear a skirt?!" Ryuji argued.

"Because you're the one that has a problem with it!" Rin answered.

"I'm pretty sure he still has the skirt." Lightning added. They were going through files they'd found on the Blue Night. Rin had popped in and made a comment on how many earrings his boyfriend owned and that had started this whole thing.

"Do you still have it?" Rin wondered. "It's none of your business!" Ryuji griped. "It is, cuz I wanna see you in it!" Rin shot back.

"What is your obsession with me in a skirt?!" Ryuji finally put down his papers and looked at the half-demon. "Cuz you'd look hot in it. Duh!" Rin rolled his eyes. "There he goes, acting like a teenage girl again." Lightning snickered. "Dad, shut up!" Rin groaned.

"Definitely a teenaged girl." Lightning confirmed. A folder hit him in the face. "Do your damn work!" Both boys yelled at him.