Rodeo is perfectly aware that he isn't much of a match for Sarge if he actually starts fighting back. He might be slightly taller, but his best friend is broader, meaner, stronger, and better trained than him-- not to mention less injured right about now. Rodeo knows he's a wounded dog, knows his best friend will surely wreck him if he fights, but he knows it's what he needs. Sarge should understand that. It's not enough just to feel his own fists hitting flesh-- he needs the crush and the bite of knuckles thrown back at him, needs it to give this anguish and rage some kind of closure. If he just steps back, just lets it end without the fight, this will all stay built up inside. Bitter anger is a terrible thing to hold against a friend. He can't hold on to this, not in here where he needs Sarge, needs to trust him, lean on him, depend on his backup. With anger like this left to seed and grow, he doesn't know where his head will be tomorrow. A fight is the only way to release what he's feeling, and it can't just be one-sided. Sarge needs to put his hands up. They need to settle this and let it be done.
Rodeo reaches out, grabbing Sarge by a fist in his collar, pressing his knuckles against his brother's throat as he shoves him back against the edge of the bunk. His eyes are crazed, but he hopes he conveys the fact that he ain't coolin' down until Sarge gives him what he demands. "I swear to god, motherfucker, if you don't fuckin' man up and hit me I will take this to somebody else and land in solitary." Because there's no way, with rage like this, that he could fight someone else and not wind up killing them. "You wanna kiss my sister, you best be ready to fuckin' fight me. Quit bein' a fuckin' bitch. Get your hands up asshole, fuckin' hit me!"