It happened on live TV on the show called Password
The word Carol's partner had to communicate to her by giving her a "hint" word was Tweet. So the guy said, "Twat." Carol said, "Excuse me?" Meanwhile Elizabeth Montgomery, the other celebrity player, was falling out of her chair laughing. The guy says, "Twat" again. Suffice it to say, neither of the celebrities guessed it. After the round was over, Carol insisted the MC tell them the word they were supposed to guess and he told them "Tweet" so Carol asks her partner why he said what he did as the "hint." He says, "Well, Twat IS the past tense of Tweet."
It was hilarious, of course, when she was telling it on Leno.