Nuts is the song that Marceline sings after the Ice King goes crazy in her house. This song is about her conflict towards him, because while a part of her wants to like him another part hates that he constantly hangs around but doesn't even know why.
You're so annoying, you pitiful old man,
I'd like to help you but I don't know if I can.
I thought you were nice, but you're really, really, really not
Every time I move eventually you find me, and start hanging around
Just another excuse just to see me man it's getting me down.
You know I'm actually glad to see you,
Maybe I'm the one whose nuts.