Cape Town - Now that his work in London is done, Michael Phelps has gone public with his girlfriend, Los Angeles model Megan Rossee.The mystery blonde that swimming superstar Phelps was spotted out celebrating with in London is a cocktail waitress, according to the Daily Mail website. The pair has been serious since January this year, but kept their relationship under wraps while Phelps was preparing to become the greatest Olympian of all time at the 2012 Olympics. “Megan thinks Michael is very funny, kind-hearted, loves hanging out with him and is just as athletic. She loves to keep in shape, so they have a lot in common," a source revealed.“She was with him in Omaha, cheering him on at the Olympic trials and has been playing the part of devoted fan and girlfriend."Phelps, 27, made history at the 2012 London Olympics when he became the most decorated Olympian of all time with 22 medals. He also holds the all-time record for gold medals - 18 - double that of the next highest record holders.Phelps, who hung up his swimming trunks after his London exploits, announced that his next goal will be to work on his golf handicap under the watchful eye of Tiger Woods's former coach Hank Haney in a new series of the Golf Channel's The Haney Project.Phelps has also signed on with Louis Vuitton as part of the fashion brand's Core Values campaign.