Credit: Steve Granitz/WireImage

Party of five! Molly Sims is pregnant and expecting her third child with her husband, Scott Stuber. The former model announced the news via Instagram on Tuesday, August 9.

"Ummm…so this happened!!! Baby Stuber #3 is on its way!" Sims, 43, captioned a photo of her baby bump. "#LOVE #grateful #CANNOTBELIEVETHIS #ourhailmary."

In the pic, the Las Vegas alum holds up a silver "3" balloon outside. She shows off her growing belly in a black spaghetti-strap dress.

Sims got choked up while discussing her pregnancy on her official YouTube channel. "We're so excited," she said, tearing up. "This is happening. This is like our Hail Mary."

"We never expected it would happen," she added. "This is such a true surprise. I think that's why I'm so emotional."

Sims and the film producer, 47, tied the knot at the Frank Cafaretta Vineyard in Napa Valley, California, in September 2011. They are already parents of son Brooks, 4, and daughter Scarlett, 16 months.

Last year, while Sims was pregnant with Scarlett, she opened up about motherhood in an interview with Fit Pregnancy. "I would have been a good mom earlier, but I didn’t find my prince until I was older," she said that January. "I don’t regret starting later. Everything I’ve wanted to do, I’ve done. I lived in Europe for six years, waitressed, worked at a book company and in a law office."

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