The scenario is that you’re both at someone’s party, and you’re
sneaking into an empty room in the house for some alone time together.
It starts with you both entering the bedroom passionately making out.
Once you’re both next to the bed, your partner starts to caress your
butt. You start to get turned on by this the more he does it. Then he
gently turns you around, bends you over, lifts up your dress to expose
your bare butt, gets on his knees behind you, and proceeds to literally
kiss your naked butt (the cheeks, the crack, everything). While he does
so, he touches, massages, and buries his face in your booty. You’re both
enjoying this a lot.

