You do absolutely nothing. Just sit back and watch. Your instincts are there for a reason and you should never doubt them. Even if there is nothing serious going on, there is definitely something going on that you don't like or should accept. Everything done in the dark will come to light but try and I know it is hard but try and stay cool. Freak out in private but stay cool around him.

I think you should keep your guard up but don't pressure him too much-it'll cause more stress. Just keep watching... If it gets really bad and you're very uncomfortable, maybe the relationship won't work...