Sans: Why didn't the skeleton go to the party?
Papyrus: Because they looked like me?
Sans: ... Sure.
Skeleton and the Party
Explanation
Explain Bear
Okay, you're Sans, a skeleton, and clearly not the sharpest bone in the bag. You tried to tell a joke, but it's so bad it's funny, kinda like your brother. See, the joke is that there isn't really a punchline. The reason the skeleton didn't go to the party is never revealed. And your brother's guess is just so random that you just agree with it to end the conversation.
Undyne
No, because he was too cool for it
Septos varon
Undertail
Lust sans
Ohh wow~ That's not cruel what so ever~
Red
Red: No you dumbass it’s because he had no body to go with! Sans: At least Someone one gets it!
Anonymous
undertale coments in depressing jokes! Nice