Breakup rumors be darned: On Saturday, Jessica Simpson and Tony Romo looked every bit the happy couple at N9NE Steakhouse in Dallas. "They were holding hands, in a good mood and happy," a source tells PEOPLE. "They looked like they were on a date together." The public display of affection was in keeping with the couple's last high profile date – Simpson's sister Ashlee's wedding, where they were "kissing and holding hands throughout the night." Simpson and Romo shared a cozy corner booth in the restaurant where they "looked happy and were laughing and smiling," the source said. Romo ate a Kobe burger while Simpson tucked into a steak. They also ran into Romo's Dallas Cowboys teammate Isaiah Stanback and his parents, and "stopped to say hello to a guest on their way out and played with her beautiful baby girl," before leaving together, all smiles.