Crossword puzzle clue "you'd never have guessed but"

"You'd never have guessed, but ..."

"I'd have never guessed!"

"I never would have guessed it was a toupee," maybe

"Could you have guessed that?": 2 wds.

Sounds you might make when I say "Would you rather watch your parents have sex or have your parents watch you have sex?"

"I wouldn't have guessed that"

"I should have guessed as much"

Never, never, never