Ashlee Simpson joined boyfriend Evan Ross at his mother Diana Ross's Los Angeles concert after-party at Hollywood hotspot Aventine Trattoria, where the new couple was spotted "dancing and kissing" throughout the night.
"She was nice and said hello to Diana," says a source. "Everyone was in a good mood and Ashlee just blended in as Diana's son's girlfriend."
Later in the evening, Simpson spent some time bonding with Ross's sisters while he ordered a special plate of food just for her.
"[Ashlee] was talking about traveling soon with Evan," adds the source. "They were very affectionate."
While Diana Ross played hostess until midnight, the new couple partied until 1:45 a.m., leaving the venue together.
incredible night last night at #bowl thank you to everyone that came out and showed love. And thank you mom for always being so awesome!— evan ross (@realevanross) August 4, 2013
– Melody Chiu