Together:
You never should look at your mother's b**bies
No matter how big and round they are
You'll end up seeing something you don't wanna
It's guaranteed to leave a mental scar
You never should look at your daddy's penis
When he's walkin' down the hall on Sunday morn
An acorn in a nest of twigs
And underneath two fetal pigs
It'll make you wish you weren't even born
Parents are gross, parents are gross...
(Peter drops his pick into the sound hole)
Quagmire:
Parents are gross, parents are gross...