The best I can guess is that a “vestigial-tail frotteur” is a person who gets pleasure rubbing up against (without consent) someone with a vestigial tail (caudal appendage).
The best I can guess is that a “vestigial-tail frotteur” is a person who gets pleasure rubbing up against (without consent) someone with a vestigial tail (caudal appendage).
I had to look up some of this stuff!