Having to peal your ass cheeks apart to take a shit seems really unpleasant...

Why not both?

Ah, good question sir. I'd go for stinky as this seems to me the default butt state, as one goes through the hours of an active day rich in butt crack sweat. On the other hand, a sticky butt sounds absolutely unbearable. Think of the hair! No way. I don't care if it makes my buns smell like cinnamon.