RIHANNA is stepping out with her new man. The singer, who dropped Chris Brown after he allegedly beat her up, is now dating hip-hop artist Drake. The couple went to the after-party for the movie “Year One” on the Empire Hotel roof Monday. “She and Drake were attached at the hip,” said our source. After that, the duo went to Greenhouse on Varick Street and sat in the VIP area. “They are definitely together, but really trying to be discreet,” said our tipster. Rihanna’s rep didn’t return e-mails.