Is it normal that i want to have sex with someone (though it's complicated)

So I have this guy friend who I just met about a month ago. We hit it off really well the first few meetings (lunch with mutual friends) and we both have the same (raunchy) sense of humour LOL. From his body language he seems attracted to me but he's trying to hide it (moving to the seat across the table when his friend arrives). I (a girl) have literally never been so physically attracted to anyone in my life. So I really want him haha.

The thing is I'm dating someone else but I've decided to end things with him already. FYI not because of this new fellow, I've been trying to build up the courage to do so for several months already. So take it I'll be single in a few weeks.

He on the other hand is dating someone for a few months already. When I first asked him, he said he had been seeing her very infrequently. A few weeks later over drinks I asked if they were gonna become a couple and he said he would probably want to ask her to be his girlfriend, but he hasn't thought about it much. This may sound weird but I thought he was lying to test to see my reaction...because I take it that he is attracted to me but trying to hide it haha.

So bottom line we share certain friends and I think if we were to start a relationship it would look like we broke off with our partners to be with each other haha which sounds really scandalous. I only know I'm very physically attracted to him but I don't know if I want a relationship with him (he's fun but different world views). Should I just leave him alone?