The 18-year-old Jonas Brothers star took his new lady along to mum Denise's birthday celebration at the Villa Blanca restaurant in Los Angeles, according to the Daily Mail, where they also dined with Nick's older brother Kevin, 23, and his wife Danella.
Wearing a pink full-length dress and a cardigan, Goodrem, 26, carried a single red rose to the dinner.
The couple are first thought to have hooked up in May, soon after the announcement that her seven-year relationship with Brian McFadden was over.