Some quick thoughts:
"...might prove to be life altering..." For you or for him?
"...Something he is not prepared for..." He's prepared. If he weren't, he wouldn't have made this post.
"...sex life at home is pretty bland..." So he wants to spice things up with some man-on-man action. Many men regard sex with another woman as being unfaithful but can pass off sex with another man. Many women feel the same way. They'd be upset if their husband were to have sex with a woman, but another man ain't no big thing. Indeed, it might even be a turn-on.
Go for it, buddy.
--------------------------------------- added after 571 hours
OK, some further thoughts from the perspective of three weeks later:
First of all, a few words of advice. Don't let this crush you. He took a walk on the wild side, he found it fun and exciting and he enjoyed it. But now, he's had some second and third thoughts about pursuing this matter. This sort of thing happens all the time. So savor the fond memory of the one encounter you did have and be prepared to accept the fact that this might be all you'll have with this gentleman.
"...might prove to be life altering..." Yes, indeed. If things were to proceed, he could end up falling in love with you and you with him. You could end up leaving your wives for each other. Hey, stranger things have happened. I'm not saying that this would necessarily be a bad thing, but it sure would be life altering. And as you probably recall, in private messages we have exchanged I have long advocated that you leave your wife.
"...something he is not prepared for..." Well, he might have been prepared when he made this post, but as I said earlier, he's had second thoughts and now he ain't. Accept that.