A newcomer joined my dance classes.
Multiple people told me that he's just a bit creepy.
He didn't do anything terrible, mostly staring and being a bit too close.
But he also tried to flirt with a student of mine in a way that made her uncomfortable.

As the teacher, this is my problem, but I have zero experience dealing with it.

The obvious option is to tell him he's not welcome in the classes without giving him any specific reason.
But this only makes him someone else's problem.

The other option is to try and explain to him what he did wrong, since he obviously isn't getting whatever it is he's after.
But even if I tell him as little as possible, this could expose the students that complained about him.

Any suggestion?
Boosts appreciated.