TONY:
he would deny it and start assuming you that you are the one who farted.
"No! i didn't fart, it was you!"
STEVE:
he would be extremely embarrassed and keep apologizing until the next week.
"I'm terribly sorry Y/N, it was an accident! Gosh, i'm so stupid!"
THOR:
he would be so proud of the smell or the sound and make fun of it. he would laugh about it until you get pissed.
"That was the loudest one! whoa, such a smell!"
CLINT:
he would pretend that nothing happened that caused you laughing and he would admit he farted.
"Heh-heh-heh you got me babe, i thought you didn't hear it."
BRUCE:
he would feel bad even though you're fine. he keep swearing and promise he wouldn't do that again.
"Shit i'm so sorry Y/N, i was out of control i promise i wouldn't do that ever again."
LOKI:
he would be confused, he doesn't know that farted in public is an embarrassing thing.
"What was that? Did I embarrass you?"
PIETRO:
confidence level: 99%. he would goofily admit it and doesn't give a single damn about it, doesn't even sorry.
"Did you hear that? i just farted."
BUCKY:
he would be a little embarrassed but chill at the same time and start making a conversation about it,
"Why haven't you farted in front of me? are you terminator?"