Concentrating on your kids now and having fun with them, is not "doing nothing." You need to detach from your w right now though. Detaching does not mean "ignoring." Also, you can address the "letting yourself go" part by GAL, exercise, looking good, etc. Just do it, don't point these things out to her. She will notice. Stop asking her how things are going with om. Very unattractive. What, are you her gf now?? Also, stop asking and giving any info at all to these best friends of yours. Become mysterious to them too. Offer nothing, especially how hurt you are. Detaching from your w doesn't mean you stop talking to her. Big difference. The prob with LBS is that they tend to talk way too much. No more talking about the marriage, no more temperature taking. Give her polite, but short answers. Do not get sucked in. Just don't engage, don't show any emotion at all. If she tries to escalate, put an end to the conversation and walk away. Stay calm and civil toward her; do not initiate any physical contact at all. No hugs, kisses, sex, etc. You do not share your w with another man. Period. Stop taking her out on dates until om is out of your lives. It seems that you have been making her feel special enough lately. Enough now. Again, be polite, but detach from her emotions; and yours.