NEW YORK — Being a sex symbol has its dangers, as Usher learned firsthand at his New York City concert.

The crooner brought an ecstatic female fan onstage Monday night for a serenade of his sensual song “Trading Places” at Madison Square Garden. He sat her on a couch while he caressed her.

Then, after they changed positions, the overexcited fan tried to move her leg to get closer to him. Her stiletto boot heel knocked him in the nose.

The fan tried to smooth things over by massaging Usher’s face, but there was no need: Usher wasn’t hurt and cracked a joke about it.