similar to the dutch oven, a cake check is when you let one go under the covers and keep it sealed. you then open one side to let the air escape and it hits you in the face just like when you open up an oven to check on a cake.
you're sitting in bed with your significant other and you let one go (silently since it will work best that way), then open up the end near your partner's side and say "cake check!"
Ved: Why does that guy, Delroy, always stink
ADon: Because after he has sex with a dude, he also eats munches their cake too
Ved: What a disgusting, cheek busting cake muncher
Adon: Stay away from that creep