So, it’s been stated in DBZ that the Super Saiya-jin transformation brings with it some personality changes (maybe caused by adrenaline, idk). Goku and Gohan kinda shed these changes with the original transformation when they become used to them in the Hyperbolic Time Chamber, but SSJ2 is a different story. When Gohan is SSJ2 he seems much more aggressive, colder, and more violent than normal. How that translates to sex is probably just a rougher, harder fucking, which seems to have taken Zangya by surprise here. I don’t think she entirely minds it, but he’s definitely a much more aggressive partner in this form than the Gohan she’s been paired with in my work up to this point.