The creators actually said that PB and Marceline once dated. So, this might mean they're hooking back together
Adventure Time Quotes
Adventure Time Characters | adventure time princess adventure time original character neon ...
adventure time theory - Google Search
"Interesting Adventure Time theory I found." Very deep. With Adventure Time you never know... but it would make a crazy adventure time kind of sense.
Adventure Time Theories
Adventure Time...even though we know about the ghost being finn's past life, i still love this theory
Adventure Time Theories - lemongrab is weird
Adventure Time Theory - Enchiridionhttps://www.facebook.com/groups/comeongrabyourfriends/
this kind of says the same thing as the one from before, but that one goes into more detail specifically about her mother.