I understand. I appreciate the advice. And this is not the main crux of why I'm writing anyway. Nothing but interest has really happened with this person anyway. I'm more interested in find out whether others live with companions - not romantic and how that works.
That said, to me divorce isn't as easy as you point out because marriage (for me) is not about romance and sex. It's about companionship, friendship, and family. If I were just in love with my husband breaking up would be easier! But he's the only one who can assure me when I'm anxious, we have a child together, I consider his family my family - so breaking that apart just because I don't want to have sex or candle lit dinners with him seems silly.
But do I want to give up sex and romance entirely? Don't know. He seems ok. He would prefer we have sex, but he loves his GF and she's into his kink and she doesn't want more so...