I'm in love with him now. Still, sometimes I think that maybe he's done this kind of thing before or that he will in the future. He said that he has only cheated once on his wife, to whom he's been married for almost 20 years. Is this a mistake?
As infatuated with him as you may be, do you respect yourself and what you are doing? Please use your doubts and your suspicions that he has manipulated other girls like this before to inform your actions. I understand that you might not want to get this teacher into trouble or to cause yourself embarrassment by reporting his inappropriate behavior, but I would appeal to you to take action so that this stops. Through his sexualized behavior with you, he has demonstrated that he should not be in a position to associate with young women on a college campus.
I am sure that your college's counseling service, your parents, your friends, and family members will rally behind you to support your stopping this man's continued abuse of his female students. This is not a romance or a great love, as much as you might want to conceive it as such. Break off all contact with this man. Thanks for being courageous when it seems easiest and safest to do nothing.