Lessons I have learned from popular culture:
Men who wear ascots are always douchebags.
I have mixed feelings about this story.
I actually appreciate what I think it was trying to do, which seems to me to have been a) to give the newlyweds a bit of a trial by fire, and b) to turn the focus a bit more on Mary Jane.
Combining those two aims into a single story is actually better than trying to do them as separate stories, because no matter how handsomely Peter is drawn, the whole point of his relationship with Mary Jane is that he's the nerd who got lucky, so if HE'S the one who's tempted, it kind of makes him look like a jerk.
And realistically, since I believe this was when Mary Jane's SUPERmodel status was being played up, if either of them was more likely to be on the receiving end of attempted seductions, it was going to be Mary Jane, rather than Peter.
That being said?
This dude actually would have been more subtle if his name was Snidely Whiplash LeDouchebag, so it's not exactly doing Mary Jane any favors to show that she's still attracted to him even after he makes it pretty clear that he's a total fucking scumbag. Granted, any guy who tries to seduce another guy's wife is going to seem at least a little bit assholish, but they could have played up the "What sort of man neglects a wonderful woman like you?" angle, so that it at least SEEMED like he also had some genuine regard for Mary Jane as a person.
Also, Mary Jane not telling Peter? Not good. This was something that Peter and Mary Jane NEEDED to talk about - hell, it's something that they probably needed to FIGHT about, at least for a brief while, which would have had WAY more dramatic tension than Smarmy McAscot going MUAHAHAHAHA I HAF U NOW MY PRETTEH - before they finally reconciled, like the mature adults that they are. Not only would such a storyline have OMG BROUGHT THE DRAMA, but if done right, it would have left the Peter/MJ marriage in a STRONGER place than it was before.
So, full points for intent (assuming I'm reading the motives behind this story correctly), but the execution has some problems.