Two mothers-in-law.
Well, that's the edamame.
She sells shesells...I mean...Sea sells sea shells...dammit! She's...a beachside entrepreneur.
Watching your mother-in-law backing up towards the edge of a cliff in your new BMW.
One is against the law and the other is sick bird.
More than one mother-in-law.
The joke is its own pun-ishment.