Molly Sims in Le Catch xo Haney

Mary Alice Haney’s Southern hospitality might have posed a problem for her new collaboration with Le Catch’s Marlien Rentmeester.

The namesake designer of Haney cut only 70 pieces of the minidress that the fashion blogger helped her create out of stretchy silk and denim with sleeves that reveal a sexy sliver of the arm. At Tuesday’s luncheon celebrating the collaboration, which officially launches today, Molly Sims, Crystal Lourd, Rochelle Gores and other friends kept snapping up the $350 style.

After all, the minidress is a steal compared to Haney’s frocks, which retail for $1,200 and up. It’s also the Los Angeles-based designer’s first attempt to work in denim.

“Le Catch is about get-it-before-it’s-gone,” said Rentmeester, who previously tried her hand at collaborating in accessories with Clare Vivier. Representative of Haney’s day-to-night style philosophy, the dress is versatile enough to be worn as a tunic over pants. “I would wear it with gladiator sandals and loafers and M.A. would definitely put a heel on,” she added.

The sisterhood of the versatile dress grew with Rentmeester’s identical twin, Coliena, who hosted the party in her Beverly Hills home, donned a black version of the frock and photographed her sister and Haney in their marketing campaign. Their mom was also milling in the kitchen, making sure guests were eating the crudités and toasts topped with chicken liver mousse, smoked salmon and avocado.

Sims definitely had food on her mind, not only because she is almost seven months pregnant but also because she was scheduled that day to photograph some food for her second book, “The Everyday Supermama.” A sequel to last year’s “The Everyday Supermodel,” the new tome is based on the actress’ experience raising a son and a daughter, both under the age of five, with another on the way. “I am stressed, my friend,” Sims said, although she looked poised and glowing in the Le Catch xo Haney dress stretched over her baby bump.

Haney never thought she would enter the maternity field. Sims kept asking her friend, “Can you design me something?” Haney’s reassuring response: “Don’t worry. It’s going to fit you,” Sims said. “I love it.”

Besides, Haney noted, “everything on Molly Sims looks good.”