Me - You don't need to defend yourself to anyone. You need to do whatever you need to do to make yourself happy. I think Michelle just misses talking with you, regardless of the reasons or who initiated contact. You are a great person to talk with. You are kind, caring and show empathy for people. It's fun to hang out with you, because you are a great person!
OK, let me be the first to say it:
"Blcccccch!" ((((spew))))
Congratulations -- you just put your stamp of approval to her affair.