Sans: "What's up."
Frisk: "I'm a stupid doodoo butt."
Sans: "Did you...did you just say 'I'm a stupid doodoo butt?'"
"Wow. I can't believe you would say that."
"Not only is that completely infantile...but it's also my secret codeword."
omg who dropped their hotdog?
what the frick frack dick slap pussy ass buttcrack lackback stupidass cupid last cast best ass less bass is this stupid shit boy watch your mouth before i frick frack diddily dack patty wack snick snack crack pack slack mack quarterback crackerjack biofeedback backtrack thumbtack sidetrack tic-tac out of you!!
Someone who would be dumber than the ass of a butt, but since an butt can't have an ass, the person who is buttass stupid is in fact the biggest idiot alive.