I like a man who has a girlfriend( doesn't seem serious)who seems to have an attraction to me?

I have been on the fence about divorce myself due to mistreatment of him toward me and my kids. I really want a happy and healthy relationship. This man works at my kid's school and i have observed him as polite, responsible, and thoughtful. I'm very attracted to him he may or may not know because I'm very careful to be reserved. He asks me questions about myself. for example he inquired if i like this gym I go to with my kids I mentioned we were at. I answered it as respectfully as i could being his girlfriend was standing right there. I asked if they were married and he said in front of her no that's just my girlfriend. i don't mean to be sneaky but i thought of ways I could get to know what he's about a little better and asked if they' like to go to a Christmas show my kids are in and maybe his girlfriend would like to help out with hair stying being that's her profession. He immediately asked if he could have my phone number. Aside from that he goes out of his way to speak to me and lingers. he touches my arm when he's walking by or away. These may or may not be signs. I really thought he'd call me by now. he didn't though and I can't tell you how much it has been getting to me. He knows 2 places he could find me now(the gym) and at this playhouse for the next weekends to come. Should i wait for the move on his part or should i show it more I'm interested in him? Should i forget it because he's involved. I would of usually styed away but i can't with this one. I'm not looking for an affair either. If anything i'm at least curious and maybe I feel a little guilty to he has a girlfriend to be considered. thanks for your time and please serious anwers only.