Your mom said my cum tastes like Captain Crunch, bitch.
Captain Crunch Flavor
Explanation
Explain Bear
Listen up, buttercup. This joke implies the speaker had sexual relations with the listener's mother. The punchline is the speaker's semen supposedly tastes like the cereal Captain Crunch, which is kinda messed up but also kinda funny. It's funny because it's ridiculous, okay? Now go back to drooling.