I'm going to attack my girlfriend's character on a twitch stream.
What? Can you explain exactly what you mean by attacking her character?
I'm going to question her behavior and make fun of her.
Don't put your girlfriend on the spot like that. Think about how embarrassed she will be if you insult her online.
It's not like she will be hurt or anything. Everyone is doing it.
You're her boyfriend, though, so it is clearly different. You are expected to stand up for her and not try to join in on embarrassing her!