ZAC Efron is reportedly dating Emma Roberts. According to a new report, the pair where seen full-on making out at an after-hours party hosted by Lance Bass on October 30. Zac and Emma both wound up at Lances party, and before the night was over, they were all over each other, a source said. They took each others numbers. Efron has previously dated his High School Musical costar Vanessa Hudgens, while Roberts - the niece of actress Julia Roberts - has been linked to Glee star Chord Overstreet. SS