Turn-ons? Feeling their walls around my cock as it pulsate and shoots wads of cum. Feeling my head and its undersides get engulfed in their tightness as I stop thrusting. Sensing the last bits of jizz on the tip of my dick getting wiped off nside of them as I pull out. Watching my cum slowly leak out and being proud of the little spillway of pleasure and joy I've made.
I used to be turned off by the fact that creampies are how babies are made and the risk of pregnancy, but since I've had my vasectomy, I'm in absolute with them and they're often my preferred choice if my partner doesn't want a facial.