HollywoodLife.com has learned our favorite role model didn’t touch any alcohol at the Mexican restaurant last night for her boyfriend’s birthday. Good for her!

Miley Cyrus and her parents, Billy Ray and Tish, took Liam Hemsworth out to a belated birthday dinner last night at Casa Vega and despite the 19-year-old superstar joking she had “too many margaritas” to paparazzi, an eyewitness tells us she didn’t drink a drop of alcohol.

“Miley wasn’t drinking alcohol at all,” the source at the popular Mexican restaurant tells us. “She was with her family and friends having a great time and Liam was definitely the center of attention.”

Liam turned 22 Jan. 13 and Miley surprised him with a puppy for his birthday. However, last night he also got a couple of gifts, the on-looker says.

“Everyone was in bright spirits and was sharing food with each other,” the source says. “Miley’s parents clearly love Liam. Miley was being very playful with him all night and they didn’t care at all.”

When Miley walked out of the restaurant, she tripped at one point and joked to the photographers she had “too many margaritas.” We love how sarcastic she is — and we’re glad she chose to keep her margaritas virgin!

Reporting by Russ Weakland