Yeah, adult entertainment is a bad reference, you can see girls faking grip all the time. A lot of guys look big on screen and the girl can get their hand around it.
I'm under 5.5 I think(haven't measured in a while and probably won't measure for a few months) and I had a lil Asian gf who could just barely get her fingers to touch. I have smaller hands for a dude and can't touch my fingers around a toilet paper roll. So as long as I keep dating girls with smaller hands than me, 5.75 should be plenty. That's my minimum goal, I think I want 6.25 and I'm not sure if that's realistic or not as I already gained at least half an inch.