I know about several, the Milodan male "Doggystyle" scene (if you have a knot), the Haley x Ellie x PC threesome (if you have two dicks with knots), the anal branch of "Drain Her" scene of the Dryad/Amber, the "Fuck Ass" scene of the Milodan Infiltrator and the "Frot & Fuck" scene (if your dick...