there just aren't words. Just aren't words.
As you know-I had a long-term affair. The idea of letting it all fall together (or apart) the way your wife has boggles my mind.
I admit my actions were selfish and inappropriate. However, at no point did I ever stop concerning myself with my kids.... I can't even fathom taking the types of risks you describe here-as a parent. I just can't.
I wish I could take your daughter and like the girl in book 7 & 8 of the Kushiel series, wipe the memories clean. Because-even if she manages to get to the point of letting go and potentially forgiving her mother for some highly selfish and inappropriate actions... she can't forget and that just sucks.
FYI-BDSM in and of itself isn't a bad thing. I have a D/s relationship with GG. But, there is a HIGHER level of responsibility required if you are going to have a relationship like that. I don't know that you care one whit, but when things settle down, take a look at the libbysub blog listed in my signature. It's written by a lady who is a 24/7 submissive AND has 3 children. She and her husband/master have a CLASSY way of handling their BDSM lifestyle and their family. Something that doesn't leave room for their children to suffer as your daughter is.
HUGS, I can't imagine that anything will make you (or her) feel better right now. But, hopefully in time your daughter will realize that her mothers errors don't have to control her own life. She's still free to build the beautiful and amazing life she always was.