When you're about to ejaculate, you stuff the tip of your penis onto the buttcheek of your partner's freshly shit, unwiped ass, making the semen spray in all directions over the buttcheek, looking like a poorly made cheesy grease bomb.
Commonly misrepresented as "Spongebob Squarepants", Cheesebob is a cartoon character who lives under the sea, and has an impressive array of friends.
Nobody really knows why Cheesebob was changed to Spongebob when he clearly is not a sponge, but a block of cheese.