I was thinking about the relationship between Princess Bubblegum and Marceline the other day... well I have been since "Burning Low" aired...
Anyway, while I was on vacation we did a lot of traveling, so that meant a lot of down time in the airport and on different airplanes. I've got a few episodes of Adventure Time on my iPod, so I watched through what I had to pass the time. One of the episodes I've got is "Go With Me", and as I watched, I got to thinking; if Marceline is a girl, and actually knows what a girl wants (she's over a thousand years old, she should know by now), then why is her advice so terrible?
I couldn't just brush it off as another prank of hers, because even when she's just joking around, she's always come around in the past (as far as we are aware, at least).
Firstly I got to thinking, who is Marceline really pranking? Sure, she's deliberately giving Finn bad advice for how to ask Princess Bubblegum to the movies, but all of her mucking about ends up affecting Bonibell a lot more than Finn (the poor girl got wolves released into her bedroom for pity's sake). I was thinking that perhaps Marceline is using the pranking business as a facade for some revenge scheme against the candy heiress, but Marceline doesn't come across as the vengeful type.
Then I thought...
Marceline isn't pranking anyone or out for revenge at all...
Marceline is jealous!
She doesn't like the way Finn is flirting with Princess Bubblegum, so she gives him the worst possible advice, advice that she knows from experience will backfire in the worst possible way. Remember she believes Finn is trying to ask Bonibell to be his girlfriend. She's sabotaging Finn's attempts at wooing the princess every step of the way.
This is my theory, and I'm sticking to it.
Sugarless Gum: 3
Haters from Cartoon Network: 0
An unrelated note, I've got Chapter 1 from "Adventure Time with Marshall and Gumball" re-edited and posted to AO3 here: [link]