When your ex-significant other suddenly becomes desirable again once somebody else starts hooking up with them. Similar to a child getting angry when someone else plays with their old, used toys.
Also abbreviated as UTS.
Also abbreviated as UTS.
Guy that is experiencing the diabolical irony of Used Toy Syndrome: "Dude, I know I'm the one that broke up with her and all but I think I'm getting mad UTS now that that bro over there is talking her up."
by lindorchocolates September 11, 2011