"Anytime you put on the mouthpiece of somebody that you're not, there's a professional responsibility to get it right."
-- Jodi Picoult
As we know, most readers and writers of m/m romance are female. And, because of this, most gay romance follows a very heterosexual pattern: one person is intensely dominant and handsome; the other is passive and pretty. This is pattern is troubling enough in heterosexual romance. In gay romance, it's just plain wrong.
Links and advice under the cut.
While I am not a queer man myself, I have collected some resources:
How To Slash Better: http://neo-prodigy.livejournal.com/969225.html (warning: this guy was PISSED when he wrote this)
Minotaur's Sex Tips for Slash Writers: http://www.squidge.org/~minotaur/classic/eroc.html
And these two phenomenally helpful and entertaining pieces:
And a little help here: http://www.reviewsbyjessewave.com/?cat=1741
That being said, don't believe everything you read up there. Some articles, I've noticed, contradict others. Read them knowing that being a gay man does not make someone a reliable source on how all gay sex happens, just how that particular gay man sees it.
Some things are facts (lube is necessary) some things are guidelines (guys don't cry) and some things are questionable opinions (gay men find gay sex hot because it's degrading).
And, lastly, for our kinkier folks, what you need to know when writing BDSM.