My grandmother's ninety. She's dating. He's ninety-three. They're very happy; they never argue. They can't hear each other.

A stand-up one-liner built on affectionate exaggeration: the setup presents an unexpected, upbeat image of very elderly people dating, then pivots to the punchline that their happiness comes from an inability to hear one another. The joke plays with a familiar stereotype about couples arguing, flipping it into a comic “solution” rooted in age-related hearing loss. Beneath the humor is a gently optimistic note—romance and companionship can persist late in life—while also acknowledging the practical realities of aging. The rhythm (short sentences, escalating ages, abrupt final twist) is typical of observational comedy designed for quick audience recognition and release.