Tuna Sub Backwards

Tuna Sub Backwards refers to a series of memes asking people to spell "tuna sub" backwards, resulting in "bus anut," a catchphrase that sounds like "bust a nut," a slang term for "ejaculate." The earliest known meme online to share the joke is a rape sloth meme posted in 2013. The joke becoming increasingly popularized in memes , mostly image macros , throughout the 2020s.