The couple, who is said to have split in late October following a brief romance, were photographed on a dinner date at Kiwami Sushi in Studio City.
"They were engulfed in their little world of conversation. They were into each other and not noticing anyone else around them," People magazine reported, quoting an onlooker.
Jennifer, 24, and Chris, 37, "Seemed to be just content with each other. He was really listening to what she was saying," the source added.
Chris split from his wife, actress Gwyneth Paltrow last year but the couple, who share two children together remain close.