Bubbline

Etymology
.

Proper noun

 * 1)  The ship of characters  and  of the animated television series .
 * 2) * 2015, Jessica DiCicco, quoted in Kyle Butcher, "Supa DiCicco", Blank Gold Coast, April 2015, page 46:
 * "The fanfiction actually began to seep into the show. The 'Bubbline' relationship between Marceline and Princess Bubblegum was never intended, but because it was a fan favourite, they're focusing on it a little bit.
 * 1) * 2018, Stephanie Chang, "When 'Bubbline' Became Canon", Her Culture, October/November 2018, page 69:
 * I don't think there was a singular emotion to describe the moment Bubbline became canon.
 * 1) * 2018, Jordan Currie, "Canon, at last!", New Wave Magazine (Ryerson University), Fall 2018, page 10:
 * Still, intrigued by Bubbline, I'd occasionally check in on the fandom to see what was up with their relationship.