A Tummy tugger is someone who is exclusively sexually attracted to a person who is overweight, sometimes even weighing more than the tummy tugger themself.
Josh: If you date one more fat girl I swear to god, I'm gonna start thinking youre a Chubby Chaser.
Jacob: I am not a Chubby Chaser I swear!
Andrew: You're right, you're more of a Tummy Tugger honestly.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi