when having sex, you pull out of the dog, cum in its bowl and mix in some kibble. Mix it with your dick and share it with your dog...while singing "when the saints go marching in"
When 2 people are having anal sex and the giver takes out their cock after ejaculating into the receivers anus. Then the receiver defecates onto the givers penis, then forms the shit around the base of the penis but not the tip which creates the Dirty Boswell