I assume you are a female since he calls you mom. He's gay, but I guess he's bisexual too since he had sex with you. Are you children grown, roundabout his age. Do you have a spouse? Depending on the answers to these questions, you may have to forget about him. He's half your age and more than likely would not want to pursue a relationship with you, he would more than likely have to be a dad/stepdad to your kids and more than likely he's not ready for that kind of relationship. I would encourage you to speak to him again and express how you feel in terms of your guilt about what happen not necessarily the attractive feeling you have for him. You think you are falling in love, what makes you say that?
'Tis better to have loved and lost than never to have loved at all. Alfred Lord Tennyson