What is Usfb?
1.
Under Skirt Finger Bang. Surreptitious digital penetration beneath a free-hanging garment extending from the waist down. Sticking in your finger under cover of concealing clothes. Sneaking a quick, hidden sexual act. Noted in Wonkette.
You can’t see it, but that dude’s other hand is pulling the USFB.
I didn’t go for the usfb, but there was a bit of over the pants rubbing.
See
2.
Under Skirt Finger Bang. From one of the first posts on LastNightsShots.
I'd USFB her. And her friend.
See