At the Watch the Throne concert in Birmingham, England June 22, the E! reality star, 31, and the 16-time Grammy Award winner, 30, stood side-by-side as their respective loves Kanye West, 35, and Jay-Z, 42, performed on stage.
"Kim and Beyonce were dancing all night! They even went into the mosh pit!" a source tells Us Weekly. "It was the most hectic thing ever!"