It was to preserve the illusion, yes, but also, you know, love. I mean, I think that "Stephen" at least cares about his wife even though he's not in love with her. In my head, something happens at some point, maybe she gets actual proof of his cheating or there's something else that provokes her, and they have a big, explosive argument, where she's like, "No! You will sit there and you will not say another word while I talk!" or something similar and he kind of immediately obeys to her, almost on instinct. It surprises them both. And then they talk, and she realizes he's much closer to gay than straight, and instead of divorcing, they come up with this arrangement.

I haven't figured out how their children factor in, if they even have any yet. It's still sitting half-formed in my mind.