When you play videogames for so long that you piss off your girlfriend. Comes from the MM0G
Oops, I played EverCrack
for too long. Now I have girlfriend aggro.
When your girlfriend (or boyfriend in some cases) tries to take your attention off what you're doing to make her the focus of your attention.
I can't run SM now, I've pull some Girlfriend Aggro and I can't shake her off.
When you're strolling down the land of make-believe and suddenly a ferocious beast with powers far surpassing your own attacks you out of nowhere- only this time it's in real life. When your girlfirend wants some attention, she'll get it one way or another.
Player 1: Hey, after this run, I'm gonna have to bounce.
Player 2: Why?
Player 1: I've got a little girlfriend aggro here.