1. "He swallowed his erection to the root" - Why is it always to the root? What is this, a forest of penis trees?
2. Lack of lube! Or (and this is almost worse) use of inappropriate substances as lube. C'mon, butter couldn't actually have been a good idea, could it? And isn't soap, like, the opposite of a good idea? *is probably exposing lack of rl experience here...*
3. Lack of condoms! Dude. Just because butt sex doesn't lead to babies doesn't mean you should skip safety. And if the butt sex in your universe does lead to babies then... I don't have any words for you. >_<
4. "Their tongues dueled for dominance" - No dueling unless someone smacks someone else with a glove. And how did they fit those swords in their mouths? *CRASH* *BANG*
5. Cerulean. Eyes. Or ebony anything. 'Nuff said.
Edit: 6.
livia_carica reminded me of one that I can't believe I forgot. "Alabaster." >_<