To me, there's something hot about someone pulling a dick, dildo, anal bead, etc. out of their ass and for a moment a white gooey substance sometimes drips out out the guys hole. Obviously it's the mucus that's inside the anus but I like to pretend it's cum. Real come dripping or even squirting out of a guys puckered asshole is even hotter.
For example, watch at 03:01, watch this guys asshole after he pulls out the last anal bead...something drips out of of his asshole and GOD does that get me hard.