Is this guy interested in me or something?

I am a guy, and straight, theres a girl I'm into etc. In some of my english lessons I used to notice a guy watching me, and I used to think nothing of it... until I noticed it happening every lesson, he seemed to be watching my lips and eyes mostly. He is quite an unusual person, and takes pride in being strange, he scares some people by being different. I then got the misfortune of being moved to sit next to him in the next term, and he used to watch me out of the corner of his eye, sometimes even turning to look at me (it doesn't help that he has poor hygiene, bad breath and his jumper is plastered with dandruff!). He breathes heavily when watching me, and seems excited to talk to me. The other day, I swear he stroked my leg!! It is really concerning me, especially as I have no interest in him, I know for sure I'm not gay! Is there a way I can confront him to explain that the feeling isn't mutual, and I'm not interested in him or any other guy at all? Help please!!