OK, I'll bite. He said "sauce for the goose..." And I said "good for the goose..." Technically, I believe his quotation is the correct one. But mine is in common use also. I'm willing to forget that one as a justification, although I like it's simplicity.
I think it's fine for him to enjoy the physicality of pleasure with other women (practicing safe sex, of course) because:
1. It's his life and his choice.
2. Actually getting out there and living a single lifestyle is the one thing that has the power to awaken the sleepwalking WAS. That is, this will make her question her actions in a way that nothing else will. What is is the bad Gov called it, "crossing the ultimate line"? Love it, I imagine a boundary at the bottom of my booty, but so be it.
Yes, when the WAS sees that the object of her disdain is not repulsive to others, in fact, is DESIRABLE to other women, it shakes their determination. They wonder, "wait, did I leave something of value in that trash that I put to the curb?" This re-evaluation is a good thing. No reason to put it off, if the LBS is not morally constrained from doing it.