I hate to ask this, but do you know that his wife asked that of him from anything but him? That seems very odd to me that she would remain married to him but encourage he seek other partners...it'd be easier on them both to just divorce. :/

I think, respectfully, that a relationship solely based on a sexual basis is a lot riskier than one that's based out of emotions first, especially if it's online. That leaves you vulnerable to a lot of unsavory types. I don't think it's at all unusual for you to develop feelings for him, as I think it's hard to share something like that with someone over a length of time and not develop at least something...but I don't think he has any intention of reciprocating your feelings outside of a sexual context.

I'm really sorry Rio. I know this musn't be easy to come to terms with. But you're doing yourself a huge favor by removing yourself from this.

Take care Rio. I am praying for you.