Everything's been said that I might say or agree with.
OW sounds like my H's OW. She actually sat in marriage counseling, crying, saying "I love you (to her H), but I love (lwb's H) too!"
Can't have everything hon!
Oh and how sad that OW's kids know what's going on. If she is any kind of mother, you would hope that would affect her. Like Rob said, if this IS an MLC for OW, I hope for her kids (and H, if he still wants to be married) that she comes to her senses soon.
You haven't failed. You are doing great.
The guilt you feel for H is normal. And H is (maybe without realizing it) is playing into it for his benefit.
Cry away, Sue. The crying will stop, it always does for me. Then you pick yourself up and move on.
