Ashlee & Jessica Reunite (Cause Chaos) in London

As Ashlee Simpson celebrated her debut in last night's London production of Chicago, her big sis and her father were right there to share the spotlight ... and offer their support, of course.

After Ash's performance, Jessica and Joe met up with the youngest Simpson sister, only to be greeted by a swarm of photogs and fans. Jess and Ashlee ducked into their car while Joe thanked the crowd for showing up. The trio tried to make a clean getaway but once they reached their destination, the flashbulbs began sparking right on cue. There was so much commotion that it was almost impossible for them to walk and see where they were going. It doesn't matter where these girls go, they always seem to make waves.