Justin Bieber and girlfriend Selena Gomez are officially young wedding crashers. The twosome happened to be having dinner in Malibu when they reportedly heard Justin's song being played at a reception.

That's when Biebs and his ladylove popped in to say hello. No doubt, the girls at the wedding enjoyed taking plenty of photos with the 17-year-old teen sensation.

Along with the above video, one of the bride's family members posted:

    "Last night at my cousin Jeanine's wedding reception, out of nowhere, Justin Bieber shows up while one of his songs was being karaoked by one of the wedding guests."


Find out which song was being played at the time ... after the jump.