Steve Rogers-
Steve only gets jealous when he spots another man trying to flirt with you. While he typically lets you handle the situation yourself, if you have trouble getting the man to leave he will step in. He will fight the man if he has to.

Tony Stark-
Tony hardly ever gets jealous. He is the famous Tony Stark after all, and he trusts you won't leave him. But every now and then when you are at a bar or a party, some drunk will try and flirt with you. When this happens, Tony will usually stand in front of you, and calmly get the man to go away.

Bruce Banner-
Bruce gets jealous more often than he admits. He is terrified of losing you to someone who isn't a danger to the world. Whenever someone else flirts with you, you rudely tell them to go away before turning to Bruce and planting a kiss to his lips.

Clint Barton-
If Clint feels like someone is flirting with you or just simply gets jealous, he won't contact the person directly. Most of the time, he will approach you and put his arm around you or kiss your cheek. If that doesn't send the message, he will call you 'babe' or some other pet name.

Thor Odinson-
Despite being a literal god, Thor worries you'll find someone you think is better. There have been a few instances where men in bars and parties have tried to flirt with you. When this happens, he will usually grab the man by the shirt and scold him for flirting with you. This typically scares the living daylights out of your pursuer. Thor will then come back and give you a hug.

Loki Laufeyson-
Loki is very protective of you, and if he spots any other asgardian admiring you, he will be sure to send a message that you are taken. In more public settings, this includes holding your hand or kissing your forehead. But if it's a more secluded situation, he isn't afraid to fight for you.

Bucky Barnes-
When Bucky gets jealous, he will try and insult or humiliate whoever is flirting with you. He makes sure they get the message that you belong to him. There was even one incident where he had to fight off a drunken man trying to grab you.

Pietro Maximoff-
When in public, Pietro has spotted guys checking you out before. Most of the time, he shrugs it off. He will simply hold your hand and smile, proud to be the only one who could do that. However if someone tried to flirt with you, he will usually tell the man to go away, but only if you can't handle the situation yourself.

Peter Parker-
Peter is very quiet when he gets jealous, and won't tell you until afterwards. He was worried about a few of your male friends, but calmed down when you reassured him that you only had eyes for him. However, if someone is heavily flirting with you or tries to grab you, he won't hesitate to step in and protect what's his

Peter Quill-
Peter doesn't get jealous very easily, but when he does it will escalate very quickly. He has a tendency to get into bar fights the minute any drunken man compliments you. You like that he's so protective, but you also think he just likes the excitement of a fight.

Sam Wilson-
If he's ever feeling a little jealous, he makes sure every guy around knows your taken. He will usually do this by putting an arm around you waist and holding you close to his side. He might also kiss you if he is still feeling jealous after this.