Molly Sims showed off her toned, sexy bikini body while on vacation in Mexico with husband Scott Stuber and son Brooks, 15 months Credit: FAMEFLYNET PICTURES

Hot mama! A little more than 13 years after she first appeared in the pages of Sports Illustrated's annual swimsuit issue, Molly Sims can still rock a bikini like it's her job. On Saturday, Oct. 5, the Las Vegas actress showed off her sexy physique while on vacation with her family in Mexico.

Lounging poolside in Cabo San Lucas with her husband, Scott Stuber, and their 15-month-old son, Brooks, the jewelry designer displayed her toned abs and long legs in a white two-piece swimsuit and a semi-sheer black sarong. She was photographed cuddling her adorable son, who covered up in a printed white shirt and matching pants.

Sims, who turned 40 in May, looks fantastic -- but she's been vocal about how hard it was to get back in shape after Brooks' June 2012 birth. "I'm still about 10 pounds away, and my baby is seven months," she told reporters back in January. "And I look at Claire Danes at the [Golden] Globes, and I'm like, 'I hate you.'" 

The 40-year-old mom said she gained almost 65 pounds while pregnant -- in part because of a thyroid condition. "My thyroid kind of shut down, so that really made it very difficult in terms of the weight loss," she explained.

"[Some] women will say, 'Oh my God, it's so easy, and I eat M&Ms and I breastfeed all day long,' and that's just not true," she continued. "I'm jealous [of women like Danes]. I wish to God I could have done it that way. But my body just didn't. And I'm so happy I have an amazing, happy, healthy, gorgeous, Buddha-like son, but I...wish it would have been easier."