Prince Harry and Meghan Markle Goof Around After Engagement Interview

Prince Harry and Meghan Markle are a turn-off .... but only when the mics are off.

Here's the couple right after finishing up their first interview Monday to the BBC announcing their engagement. You've seen some snippets already looking royal and speaking eloquently as hell ... but here they let loose after the interview ends and the mics are turned off.

Check it out ... sure, there's no sound. But you can still appreciate -- or throw up, depending on whether you're salty -- their silliness.