Justin Bartha of ‘The Hangover’ Marries Girlfriend Lia Smith

'The Hangover' star Justin Bartha married his longtime fitness instructor girlfriend Lia Smith in Hawaii.

The couple exchanged vows Saturday in front of just 20 attendees that comprised of family and friends on the island of O'ahu at Kualoa ranch, reported E! Online. The entertainment website further said that the private ceremony was held in the lagoon at the ranch and the reception was held in the valley.

Among the guests present were Hollywood star Reese Witherspoon and her husband Jim Toth, also Bartha's agent.

"Lia wore a white dress with thin spaghetti straps and jeweled sandals," a source told Us Weekly. "Justin wore a dark colored suit and burgundy socks. They were sweet together and looked very in love. He was holding her bouquet for her and walked with his arm around her after the vows."

The bride was glowing on the special day. "She had a big smile on her face and nuzzled her face up to his neck. Their family and friends seemed so happy for them and had an incredible time hanging out in Hawaii leading up to the wedding. It was a destination wedding for all," the insider said.

The 35-year-old star proposed to the personal trainer last May during their trip to Post Ranch Inn in Big Sur, California.

The couple had publicly announced their relationship almost a year ago when they were seen together on a beach in Hawaii.

Justin was previously in a relationship with actor Ashley Olsen in 2008. But the two broke up in 2011.