Jessica Simpson threw Tony Romo a 28th birthday party he’ll never forget: She licked cake off his face!

The PDA-packed bash took place Saturday night at Suite, a lounge in Dallas, where “she sang him ‘Happy Birthday,’” Kyle Kearbey of DMagazine.com, the Web site for Dallas’ D Magazine, tells Usmagazine.com.

The two really seemed to enjoy the cake, which was in the shape of a Dallas Cowboys star and had Romo’s No. 9 jersey number on it.

“They were kissing with lots of messy cake!” adds Kearbey. “Jessica had cake all over her hands and was licking her thumbs.”

Adds another source, “It was a fun night, but it got too crazy with everyone trying to take pictures and come over. It was insane.”

Simpson and Romo, says the source, “are doing great. They are really happy.”

D Magazine