b-button whore
A player who’s so clueless they just mash the B button like it’s the only thing that works. They’re basically a meaty face machine.
Text: 'You’re the B-button whore. I’ve seen better players than you.'
In-game chat: 'B-button whore! I had to dodge your meaty face 10 times!'
Voice chat: 'You’re the B-button whore of the match! You just hit B and expected to win.'