I was just in this position myself. My first love and I were chatting on the internet and he invited me over to his hotel. He is married with 4 kids and has already cheated on his wife of 13 years. You know what? I didn't go, even though I wanted to, because he was the best boyfriend and lover that I ever had. I felt the excitement of the possibility, but definitely a lot of guilt. My experience is, don't give in.