I've been reading some interesting posts to various gay yahoo groups as well as a recent article in the Washington Blade, http://www.washingtonblade.com/2005/4-15/view/columns/tooold.cfm
The author finds himself in a relationship with a boyfriend 17 years younger than he is. He frets about the age difference, but sees far more similarities than differences. He uses humor to justify whether or not he should continue to "rob the cradle" or not.
For me, I wouldn't have a relationship with a guy where I was more than 12 years older. Knowing how it is being the younger guy in a relationship 12 years ago, now I wouldn't gravitate towards anyone who is younger than his mid thirties. That would be comfortable enough for me. Again this depends on so many factors. Maturity for one. I am not a babysitter. I may be a daddy, but that doesn't mean that I want to raise a "college guy" while he's still going to college.
Guys pair up with guys because of some mutual attraction, whatever it is. Relationships work because there are far more likes than dislikes. You have to click sexually, intellectually, career wise, etc. if the relationship is going to work. So if all of these elements are in place, than a big age difference of say, 12 years, as long as the guy is at least 21, won't matter much.
I know you guys out there have thoughts on the subject. When is it cradle robbing and when is it an acceptable age difference? There has to be a rainbow o f views on this topic. What works for two guys may not work for two other guys. With love in the air, anything is possible.