Has a married person/friend ever invited you to sleep with them?

I’m a bit confused by this situation. An older friend of mine, well we have openly discussed that we are interested in each other—but due to different reasons (age, marital status, work etc) we know we can’t be “together.” In fact, both of us just want to keep it at a friendship level. My friend has expressed that he wants to sleep with me, but nothing more—he loves his wife, they are happy, and does not want a relationship. The problem I have with this is, I like his wife and I can’t help feeling that this is wrong. I am sure everyone would be devestated if she (or anyone else) were to find out. He’s said that if nobody knows nobody can get hurt. I trust my friend and never look at him negatively, and know he doesn’t have bad intentions. I’m not being naive. He said he would only do what I am comfortable doing.

What would you describe this as? I have asked him, “How would you feel if your wife was doing the same?” and he has said that he’d be upset too.

I’m just interested to see in what everyone else has to say and if you have been in the same situation as well.