Uhh, I tried on YouTube but didn't come up with anything.

I think it goes something like this:



Papyrus: SERIOUSLY THOUGH!! THAT HUMAN! DO I KNOW THEM?

Sans: * do you not know...

* ...who you know?

Papyrus: PBBBBTH!!! OF COURSE I KNOW! I WANTED TO KNOW IF YOU KNOW! I KNOW WHO I KNOW AS MUCH AS I KNOW I KNOW WHO I KNOW I KNOW! ...YOU KNOW?



Maybe not exactly these words, but it's how I remember it.

You can prolly find the actual dialogue on the Undertale wiki.