I've seen that scene, and didn't take what she said seriously. You have to understand that porn in general, and websites like Fuck Team 5 in particular, is a PERFORMANCE. I've only seen a few FT5 scenes, but the theme seems to be that the girls are in total control, and let the guys know it through a regular dose of teasing and insults. It usually makes me chuckle. One of the scenes I saw had Penny Flame, who adores uncut cock, teasing a guy for being uncut. It's all part of the gig.
If I remember right, Rebeca points to the guys cock, with the skin up, and says, "Why do you have so much skin are your dick?", then pulls it back and points to his frenulum, saying, "Aren't you supposed to have it cut here? That's why your dick won't grow?" If you really believe that a girl who grew up with uncut cock in Spain, and has been filled with dozens of massive uncut cocks, thinks that circumcision will make a guy's cock grow, then I'm sure she could also sell you a bridge. 😉