In real life take out a restraining order, on puter ignore and block. good luck with that.
If a stranger won't leave me alone.....I'd ring the police! Sounds like a stalker to me.....
In person ask them if there is anything they would kike to know. On line just giggle and go on as if they were not there and they soon won't be.
kick their a**!!...or ask them if theyre gay or if you have something on your face..
Show them the sign Avibot.