Mark Zuckerberg and long time girlfriend Priscilla Chan surprise her graduation celebration guests by getting married

It’ quite a week for Facebook CEO Mark Zuckerberg. First his company went public, making him a quick $16.9 billion, and the next day he married long time girlfriend Priscilla Chan in a ceremony that surprised their guests. Saturday their friends and family thought they were flocking to a graduation celebration for Priscilla, who graduated from University of California, San Francisco School of Medicine Monday (which was also Mark’s birthday,) but they were actually showing up for their wedding!

Mark posted the above photo on Facebook to announce the happy news (he also, of course, changed his status to “married.”) No word yet on who designed Priscilla’s elegant dress, but a wedding guest said Mark designed her ruby wedding ring, which Priscilla had not seen before the wedding.

Green Day’s Billie Joe Armstrong performed at the ceremony.

The couple met in college, and have been dating for about nine years. Priscilla is now a pediatrician, and her expertise in and passion children’s medicine helped her influence a recent major Facebook change. Earlier this month Facebook added a feature where you can indicate if you’re an organ donor, an idea inspired by Priscilla.

Mark explained: “She’s going to be a pediatrician, so our dinner conversations are often about Facebook and the kids that she’s meeting.”