Well it wouldn't be a quartet anymore...
As long as you rename it a sextet it's okay. And I'm not trying to make a dirty joke.
Its impossible to have 6 in a quartet, however, with 6 you get egg roll....
I think the operative word is "quartet"
We can bend the rules for conjoined twins.
Yes, as long as two of them don't sing.
I'll fondle you instead.