Maybe these rules apply only to well-shaven types, but yes, there are apparently dos and don'ts that are to be applied to hastiliy arranged moments and their mornings after. Granted these are from a dude in a big floating Q and it comes from Logo, the network with only one watchable show.
Rules make for unhappy people though, don't they? Sure, dumbing things down to common denominators keeps the expectations down, but it also quashes suprises and the stories you can tell your friends at brunch. Just sort of letting your instincts should work unless, well, you're just not a nice person at heart.
So yes, we do need books like the man in the big floating Q's Steven Petrow’s Complete Gay & Lesbian Manners for people that hate surprises and can't trust their instincts because they are intrinsically not nice or perhaps unkind. Granted, these books can only lead to disappointment and unhappiness. And clean-shavenness.