Been thinking about this lately. I haven't let another guy jerk me before, but I have jerked off with buddies in the same room watching the same porn. You can't help but steal looks just out of curiousity. Other guys who I know are at least mostly straight have watched me, but a good part of that I think would be them being impressed with my size.
I about fell out of my chair on the comment that being drunk shouldn't matter. Maybe not to you Bro, but I can tell you that I have done things with certain "less than beautiful (butt-ugly) women" when I was drunk that I can promise you I would not have been able to get it up with sober. I have had ugly women literally play with my cock in a bar and not be able to muster even a semi - then a few hours later I would plow her for an hour.
Soooo, I have to say that I think that I could do it under the right circumstances. I really understand the perspective that for some guys (like me) thinking about gay sex make us softer that a pillow. But I am fuckin' great with fantasies - especially when I'm drunk and watching porn. I can certainly see how a straight guy that gets paid, drinks a fair amount and watches porn could let another guy get him off.