Bubbline refers to the fan-favorite relationship between Princess Bubblegum (PB) and Marceline the Vampire Queen from the animated series Adventure Time. The term originated in the fandom as a portmanteau ship name, highlighting the stark contrast between PB's scientific, orderly nature and Marceline's rebellious, gothic personality. Over the series' run, their dynamic evolved from subtle subtext to a confirmed romantic relationship, culminating in the series finale and the 'Distant Lands' specials. In internet culture, the Bubbline template is frequently used to represent the 'grumpy x sunshine' or 'organized x chaotic' tropes, making it a staple for expressing complex relationship dynamics or contrasting personal aesthetics.