While his former flame Cameron Diaz was out getting the motion of the ocean with surf champ Kelly Slater, cameras caught JT during a concert at the MGM Grand in Vegas, honoring the one woman who's always been there for him. His mom.

An emotional Justin stopped his show, instructed everyone to grab a drink and proceeded to lead a birthday toast for "the greatest woman to ever walk the face of this earth." JT then downed his drink and playfully warned the crowd, "Kids, don't do that at home!"