It still sounds like you are affraid of insulting/upsetting your "friend"...as myself and others have stated, you need to wonder if she is truly your friend...or just using your friendship for her own selfish need...
I would tell her that you through the card in the trash because you didn't want any part of her illicit "friendship" and that your H agreed with you...I would not candy-coat it by saying "it must have" gotten thrown out with the junk mail...even if you tell her not to use your address you are still letting her think that what she did was "okay"...
So she went through a divorce...so she slept around a lot...so she is lying to current b/f about her sexual past...she is STILL trying to keep contact with a M man!!!...This tells me that she is not done with her own "journey"....and I wouldn't want to join her on any part of it either...she is bad news
