I have never thought that much about this scene other then Cowlip was FINALLY closing the door on a Stuart/Vince ending for their version of the show.
What makes me dislike Michael about all of this is that HE knows that Brian will never fuck him. He knows deep down inside. Everyone knows, so why push it. Why put Ben and Brian in a position that they have to treat him like some kid that they have to prove something too? It was a chance encounter at The White Party not some romantic romp at a B and B in Vermont.
I disagree with the idea that this was a real attempt. I think what really brings Michael to his senses over this was that Brian was treating Michael like a trick. This wasn't some mixed emotion attempt like when Brian's dad died. Where they were in Brian's bed and at the loft extended kissing and unbuckling pants. I mean if Michael ever was going to have a shot that was it.
Brian's treating Michael like a trick, shattered Michael's 14 or 15 year long fantasy of this moment. This would have been a cold fuck up against this wall at the store. Nothing real, nothing romantic. I think this is what really brings Michael to his senses and makes him fold his hand.
I don't have any idea how it would feel to harbor these types of feelings for 14 or 15 years, but in the end I think that I would be able to draw more comfort from a fantasy then I would by dealing with the harsh reality of what the aftermath of fulfilling the fantasy would be like, or the disappointment of how the fantasy wasn't fulfilled in the way I hoped for.