gauge whether or not you should go to the concert based on his response to your conversation about the flirting. No concert is worth having to deal with an aggressive pursuer like him. It's going to end in pain and frustration but less pain the sooner you nip this problem in the bud.

I do agree, he thinks the concert is a date and you're playing hard to get. tread lightly here and seriously consider opting out. it will make the clearest statement about not dating him too.