Sadly, there is absolutely nothing you can say that will help someone in MLC realize they are going through a "stage" in their life and not thinking clearly. Unhappiness with work, wife, family and seeking out a different "role" seem to be pretty common signs of it.
One of my closest friends went through the same exact situtaion as me at around the same time. I explained MLC to her, and she agreed that her husband seemed to be in it, but she was also skeptical and figured he was "gone." She started dating immediately (at least her kids were grown), moved away and never tried DBing. Well, after the divorce was final (and her husband's affair started cooling down) he sent her an apology and apparently had started sending her love letters and the lyrics to love songs!!!! Unfortunately, it's too late (at least at this point!). She has a condo hours away and a new boyfriend who she has been with constantly for the last three months.
I guess my advice to you at this point... is GAL GAL GAL, is your husband still living with you? Arrange to go out one to two nights a week with your girlfriends. Make sure you look HOT (jeans low on the hips so he can see your see black thong underware when you bend over to pick something up or sit on a chair, push-up bra, low cut shirts that show cleavage... sexy clothes!!!!). Go out with the girls and don't come home until 2 a.m.!!!!
If he asks what you're doing just say going out with the girls. If he asks about dating tell him you're not getting seriously (stress that seriously!) involved with anyone because you are still married until the last documents are signed, and feel you need time to heal. But... you never realized how attractive you are and you are just completely amazed at how young guys are attracted to older women (say this in a way that doesn't sound like you're trying to make your husband jealous. Make it conversational and stress your amazement at this). This used to bug the heck out of my husband! In fact, it still does... A couple weeks ago we went out dancing at a club where there were all these 20 year olds and some kid jumped right in front of my husband and started dancing with me!!!! Nice to keep the old guy on edge a wee bit!! LOL!!!!
There is no arriving, ever. It is all a continual becoming.