I'm thinking of playing with my fiance's soul patch while he sleeps so I can pretend to be a ventriloquist.
Why would you play with his face while he's asleep?
Because he's really happy when I touch his soul patch.
If you and your partner both know what you like, then that is a good thing for your relationships. You probably shouldn't bother your partner while he sleeps, though, even if he likes being touched while he's awake.
I think it would be cute if I move his soul patch around his face.
You two are good each other if you both like things like that and are comfortable enough to express them. Just be yourself but don't wake him up too many times or he might be cranky.