Markus Molinari and Katy Perry
05/23/2012 AT 06:00 AM EDT
A purple-haired Katy Perry
and proud papa
James Van Der Beek made their way to Santa Monica, Calif., over the weekend for their jewelry designer pal Markus Molinari's birthday party at new spot SHOREbar.
At the bash, hosted by the venue's owner John Terzian, Perry "was in such an amazing mood," an onlooker tells PEOPLE. "She liked a drink called the JoJo, and was really happy to be with her friends."
At one point, Van Der Beek – who was there with wife Kimberly – and Perry made a toast to their mutual friend and "told him how chic he is," the source says.
Chord Overstreet was also present during the celebration. – Dahvi Shira