Let me tell you something that should've been realized a long time ago.
Pen is a troll.
At least, a troll to the shippers. Pen created the Fubblegum vs. Finnceline conflict by presenting both as equally valid, as in barely possible. AND THEN he completely discards one group with the Young PB episodes and THEN stomps on the Fubblegum shippers by taking PB out of the young form IN THE MIDDLE OF A MAKE-OUT. THEN he makes a new love interest and the ship ends up working for an episode, and then seems to forget about her for a large amount of episodes and MADDENING a large chunk of fans due to providing no character development. This becomes the most possible ship. THEN he takes the most possible ship (which, by the way, WAS THE ONLY ONE THAT ACTUALLY WORKED FOR A CHUNK OF A SEASON) and trashed it (WHILE STILL KEEPING HOPE FOR THE SHIP FOR ADDED LOLZ) and put the love interest with a secondary character in a pairing that doesn't make any sense.
Now the Flinn shippers are in a tizzy because the ship didn't work, and the non-romanticists are in a tizzy too because of the stubborn Flinn shippers and the people who think a new love interest or a background character could emerge are being shut down by both groups. And the Finnceline and Fubblegum shippers are almost extinct.
See, this is all a mess, and according to my theory, intentional.
Pen, you clever SOB.