Every pop star has songs that are best left forgotten. Except who can forget these?
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Katy Perry: "Milk, Milk, Lemonade"
This outtake from "Teenage Dream" never made it on to an album, but it is nonetheless the most embarrassing song on this list. Katy cowrote this tribute to scatological functioning with Bonnie McKee, and the lyrics are almost unspeakably humiliating. "My honey dew and your banana make a treat" is somehow not the worst of it.