Sexual advances from a prospective tenant

[Marvin Meng]

So this is a first for me...

I had a prospective tenant look at an apartment last week. They asked to see the lease so I emailed them a copy of the lease. The individual next emailed me over the weekend and asked if they could look at the apartment again, and we set up a time to do it (tomorrow). They then wen on to email and text me suggestive pictures of themselves and offer me a "pat down" along with other inappropriate comments. 

Obviously this is not somebody I want to rent to or want around my other tenants. Quite honestly I think there may be mental stability issues there. My inclination is to email the individual and tell them that there's been an apparent misunderstanding and suggest that they rent somewhere else. 

BP'ers: Is there a need to be concerned that I could be discriminating against this individual here? I'd really appreciate your ideas of how you would handle this.

I gotta admit, when you landlord, you see it all...

TIA!