I think I get what your wife has been through. I have a six year old too. I had crazy hormones, got over weight and breast fed until my boy was 3. Didn't make me feel sexy at all and I did not feel like having sex at all! Now it has totally turned around. I had a bit of a time where I was in party mode over my new freedom and felt so good. My husband and I talked about getting back into poly at that time and it came about in our lives again slowly with a lot of interesting interludes.
I would suggest that your wife told you to go out and find a woman to have sex with because of her own frustration with her lack of freedom from your daughter, her body not being what it used to be and the seemingly endlessness of feeling like that. Now she has found that she can have some freedom back, her body back and be desirious of sex again. She is just beginning to enjoy that I'm sure. Try and remember that she said all that and acted like that in the past. This is now and a new leave has turned.
Do I think she should of done what she did? No! She cheated in my book. Her having sex with her friend should of been discussed with you in great detail in terms of what you could both do together in order to maintain your bond and connection. It should of been talked about with the friend and everyones boundaries and rules discussed. Of course they seem to get blown out of the water anyway after the act happens and re-thought out, but that would of been the most respectful to you.
Is all lost? I don't think so. Its not like you were blind sided. You knew that things were in the works and were not surprised or concerned. I think you should do your best to put the past behind you in terms of your wifes early childhood years and move forward. I think that you should ask for what you want from her in terms of intimacy and strive to work on your sexual relationship together before she sleeps with her friend again. If this is someone she wants to continue with then now is the time to work on boundaries and rules with the friend before they become closer.
It will be interesting to see how the energy between them changes as sometimes a bit of a sexual release is all that is needed and the desire to have sex again diminishes forever or at least a time. Use that time to regain connection with your wife. Be really honest about what you want. That is your right. She can always say no and if she does then you will have to negotiate what she wants to do and what she doesn't.
Lots of communicating to do. Get at it my friend.
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