Charlize Theron [1] and Sean Penn [2] said goodbye with a passionate kiss on Saturday before she and her son, Jackson, hopped into a waiting car outside of her LA home. On Sunday, she was spotted traveling solo through LAX. Charlize and Sean are starting to show off what started as a very private romance and have made multiple public appearances together, including at the Met Gala [3] earlier this month and at the premiere of Charlize's A Million Ways to Die in the West [4] last week. Charlize even opened up about Sean in the June issue of Vogue [5], saying that their relationship, which blossomed out of a longtime friendship, is "effortless."