I've always said that generally the best episodes of Adventure Time involve the Vampire Queen Marceline. She just messes with Finn's radar so badly that it always leads to enjoyable hijinks. This time while waiting for Marceline to come home, they sneak into her house even though they were told not to. When she does come sooner than expected they find themselves trapped and take refuge in her closet. They get a good view of Marceline just being a person and doing those things people do when they think they are alone, like nose picking. The boys try to sneak on out, and fail but they learned a lot.
Maybe too much.
This was a fun episode and I was amazed at the honesty of it. Also, I admit the moment when Finn tries to sneak out and accidently caught sight of Marceline in the tub made me have about the biggest Adventure Time laugh ever. For all his heroism Finn is just a boy and that glimpse was both mortifyingly embarrassing and way too much information. He goes back in the closet and tells Jake, "Not going out again."
Definitely not intended by the animators but as I watched this episode I flashed back to the similar scene in "Blue Velvet." One crazy part of my brain was hoping that a madly animated Dennis Hopper vampire would come in and completely blow Finn's mind.