Its time to celebrate with milkshakes from The Max! Mark-Paul Gosselaar, who played Zack Morris on Saved by the Bell, is expecting a baby with wife Catriona McGinn, according to People. This will be the first baby for the couple, and they are expecting in September. They were married in July 2012. “We are all really excited for the arrival of our new addition," Mark-Paul says. "We’ve always wanted a big family."