Just Pretending (Bubbline/Sugarless Gum)

When Princess Bubblegum and Marceline go undercover to check out a couples resort, they find how hard it is to fake being girlfriends. But how long will their fake relationship take to turn real? (Girlxgirl, Marceline/Bubblegum) *There will be smut later in this so if you don't like that, don't read*