What kind of dynamic is there between his wife and him? Are they more like very close, best friends who are fine with the other doing whatever (or whoever) they want?
Oh, and there is a big difference between "unattached" and "detached," I think.
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein