u/40below

I think this may well be an episode of The Partridge Family, but if so I haven been able to locate it.

Sometime in the late 70s or early 80s I saw a TV show in syndication in which a teen brother holding a guitar sang a song to his sister with these lyrics (or something close to them): “I’ve got a sister, really groovy. La li la li la li lo. Like an old Godzilla move. La li la li la li lo.”

The sister is seen smiling at the first line but annoyed at the second. I think it may have been Keith Partridge singing to Laurie Partridge. This wasn’t one of the show’s main performances or rehearsals, but a quick joke.