You fool you activated his trap card

Papyrus, of all people, should have realized what would come out of that comment.

Sans's reaction is hilarious XDDD

"He...he didn't, did he?..... He didn't just make a pun on ME, right?...."
"Does he even realize what has he done?...."
"Can't fire back, the one time HE makes a joke i can't fire back..... i can't, i absolutely CAN'T...."
"OH HECK YEAH, YOU ARE ON MATE!"