Bro this is a gooner pirate site, you can say pussy, ass or tits. Never say you like A.I. or we'll execute you though. You've been warned.
Anyways, you use a dynamic bone collider while the Female character typically have an uncensor that has BP in front of it. All you have to do is click the dynamic bone collider, press KKPE and goto Advance (Usually in the pussy/mouth or dick section for guys) and just enable everything the has Vagina.
This doesn't work for all scenes though. Also, it's the Vagina, not Ass.