Allosexual husband of an asexual wife explores options

I agree your analogy a point. There's a greater intimacy with sharing sex than going to see a show together, and a likely possibility that the sex partners would begin to feel affection for each other in a different way to the people going to a show.

I don't think there's anything wrong with extramarital sex as a solution to mismatched sex drives, you just need to do it with your eyes open about what the parameters are. I've been the "side chick" a lot of times and I don't catch feels every time, although I obviously like the person. Sometimes I do end up loving that person, but also doesn't mean I want relationship with them, fwb is just fine thank you very much.

It really comes down to how it's managed between the people in the situation. If I tell a fwb that I love him, that's private information that he doesn't need to share with his wife. He might not love me back, but is emotionally mature enough to recognise that 1. He doesn't have to, and 2. That's not a deal breaker. On the other hand, he might love me too, but also could be very happy with a loving fwb situation.

Just because sexual intimacy can lead to loving feelings, it doesn't mean that lives need to be overturned. Sometimes it's okay to love and not want to share more than that.
I completely agree with everything you’ve said, although it wasn’t an analogy. At least it wasn’t just an analogy, it was also literally true.
We have another incompatibility. My wife enjoys musical theatre. I do not, at all…

There were things around it I did enjoy…

Over time I gradually stopped going…

She has other friends she goes with, she enjoys it and I’m happy for her.
A helpful analogy that may also, if you’re planning on bringing it up, help your wife to understand your position.