The standing partner leans slightly forwards. The other partner kneels behind, tonguing the bumhole and massaging the pubic region.
Just prior to climax, the standing partner defecates in the mouth of the kneeler.
Then, they turn around to ejaculate over the mouth-poo.
The kneeler then tears a handfull of pubes off the stander and sprinkles them over the mouth-poo-cum cupcake.
The cupcake is then eaten by both partners.
Friend #2: Yeah sorry dude, last night I shared a Bavarian Cupcake with Steve..
Friend #1: I read about those on Urban Dictionary... I thought it was just a joke- How was it?
Friend #2: It was exactly like the definition.. tasteless and corny.