Article continues below advertisementAshton Kutcher and Mila Kunis are still crazy about each other!Article continues below advertisementThe longtime couple had a date night to remember at the Backstreet Boys' Into the Millennium summer residency at the Sphere in Las Vegas, and fans caught every sweet moment.Article continues below advertisementSource: @michaelshawnmccabeArticle continues below advertisementIn a fan-shot video from the sold-out concert on Saturday, August 2, the duo danced together in the VIP pit to the boy band's hit "I Want It That Way.