This is the nice version, in which Jack and Carl come to some conclusions on their own, and eat a lot of humble pie.
Jack and Carl catch Steve and Bucky outside a gay bar and drag them into the alley to rough them up. It’s clear Bucky’s trying to keep Steve out of it, holding his own against both of them, but there’s no way Steve’s letting Bucky take on two guys at once, so he jumps in, and Carl knocks him to the ground.
The look on Bucky’s face when Steve’s head smacks against the concrete is bad enough that Jack freezes for a second, giving Bucky the chance to deck him right in the mouth. He shoves Carl out of the way to get Steve up off the ground and make sure he’s okay. Carl doesn’t even try to stop him - he’s too worried about the blood in Jack’s mouth.
“What the fuck, Carl?” Bucky yells. “I said I’d take you on myself!”
“He just came at me - I didn’t mean -” Carl stutters, holding up Jack while Bucky holds up Steve. Steve’s not looking too good. His head is lolling slightly, and he’s clutching onto Bucky’s arm like he couldn’t stand on his own.
“Sorry - shit,” Jack gasps, spitting out a mouthful of blood. Sure, they wanted a fight, but they weren’t looking to kill anybody, and Jack knows he’d be ready for blood if someone had punched out Carl like that. They aren’t queer, but they look out for each other, and Jack would have had the same look on his face as Bucky did if it were Carl with all that blood in his curly red hair.