I'm going to call my girlfriend fucking retarded.
Why would you insult your girlfriend like that?
Because she's stupid and want to get revenge on her.
You shouldn't intentionally insult people, especially not someone you're close to like your girlfriend. You also shouldn't use terms like "retarded" as an insult. It demeans the mentally challenged and makes you come off as rude and ignorant.
I don't care and I wouldn't care if my girlfriend gets hurt. That's what I call total fuck boy shit.
If you think your gf is so stupid why don't you just break up with her?  There is no reason to insult her and hurt her.