My bro has been trying to game this girl for months now. He doesn't care about her and doesnt even try to kino with her. He has no feelings for her whatsoever. I asked him if i could makeout with the chick and he said "i dont think thats a good idea". then he was really pissy the whole night and in conversations said that i was hecka cocky. I could tell that he was angry for the rest of the night. Is it wrong to ask your bro if you can hook up with his date that he wont talk to and isnt gunna get with?

It is, but only because there are better ways to do what you are trying to do. If your buddy is gaming a girl, stepping in basically means telling him he has failed miserably. Nobody responds well to that in the field, at least nobody that would be in that situation.

My wing code would say you should ask the dude what the fuck is he trying to do? You don't game a girl for months, you game her for minutes. Any longer and its usually a futile effort. Its unhealthy for him to focus on one woman so much, especially if he isnt making any progress. On your end, dude you're out and could game anybody, is it worth pissing him off? As a wing, I believe the wingman's #1 goal is to remind his friend what the purpose of the whole night is. As you step away from the girls for whatever reason, you remind him that he has to escalate, that he's losing the alpha swag, etc. If he doesn't listen, you do your own thing. It's not a wing's job to salvage a failed set, imo.

he didn't talk to her the entire night. isnt it better to straight up ask him than to game the girl without telling him. if you dont tell him... then its like going behind his back

My point was don't game her at all that night. Confront him about it sometime afterwards, because at any venue you have smarter options than the girl he at least claims to dig. Even if he sucks at it, your job as a wing is to bring his faulty game to his attention.