What does "you'n" mean?
Great question. "You'n" is a compound of "you" and "gonna". So he is in fact saying "You gonna make me say it?" Since he is using slang and talking quickly the sound of the two words becomes connected making "you'n". I will say that this is not a known or common slang word. It is instead a result of this particular character's speech pattern, pace and accent. This is something that is common with native speakers, where stress, intonation, pace and pronunciation can and will impact words and speech patterns.