The 23-year-old actress locked lips with Alex Kelly during her stint on teen drama The O.C., and she got intimate with Evan Rachel Wood in U.S. TV show Once And Again. Barton also starred in 2008 movie You and I, which told the story of two teenage girls who fall in love after meeting at a concert.
Barton admits she prefers same-sex smooching in front of the camera, because it's less stressful than kissing male co-stars.
She tells Britain's OK magazine, "It doesn't annoy me that much. It's so much easier to kiss another girl. You're so much more relaxed filming and you can have a laugh. It can get a bit tense with a guy."