Well, a “pied-a-terre” is so much classier sounding than “shagging shack”, or “love-nest” even.
Well, that’s how they referred to Nelson Rockefeller’ mistresses townhouse less than a block from the Museum of Modern Art. Megan Marshak inherited the pied-aiterre in which Nelson died. My late MIL, a Dr, said her NYC colleagues verified it was a DITS. (NYC med term, died in the saddle.)