Ah, well, Hester...
I had 20 years of marriage of feeling nothing, so on that level I can understand. I knew the marriage was a mistake from the honeymoon onward. I tried to talk to my husband about the emotional connection, and his response was always..."I don't know what you're talking about!" And he really didn't . I was married to a brother type or friend without any emotional connection. When I would try to talk to him about divorce, he'd get mean and threaten to take our daughter away from me and throw me "out into the street with nothing." And I believed him, as he was pretty agressive about "his" property. I only left him when our daughter left for college. At that point, I didn't care if he kept everything, which he did pretty much. Anyway, coming out of that 20 emotionally barren years at 47, I was ready to meet "Mr. Right!" I made a lot of mistakes, which took a major toll emotionally and financially, allowing myself to be gullible. One of the things I heard repeatedly was, "We're not young any more and don't have all the time in the world"...re/sexual involvement. But, for me, at least, sexual involvement was emotional commitment as well.

Ask yourself, if you choose to abandon this affair in which you are involved, will you suffer any emotional repercussions? You have said you two don't love each other. But I wonder how you would handle this? My exp is that as we get older, these things take a much harder toll. If you don't love this man with whom you're having the affair, I see no reason to abstain from it. Sex alone seems a poor choice, considering your marriage.
Patty