string of ponies (tm)
A stable of guys who are available to have no-strings-attached sex with you on demand. It's like in polo, where one you trade your tired pony for a fresh one as you play the game.
She has quite a string of ponies (tm); she gets laid whenever she wants to.
I had to cut my string of ponies (tm) loose when I got serious with Barry.
I had to cut my string of ponies (tm) loose when I got serious with Barry.