On ‘The Real Housewives of Beverly Hills’ — Bravo’s hit docuseries about a group of women in LA’s ritziest zip code — catfights, tears and drama are par for the course.

But even by the show’s own outrageous standards, the March 3 episode — which featured an epic clash between Kim Richards, 50, and Lisa Rinna, 51 — proved to be a doozy.

While dining out during a girls’ trip to Amsterdam, Kim threatened to expose a shocking secret about Lisa’s longtime husband, ‘Mad Men’ actor Harry Hamlin, 63 — prompting Lisa to jump to her man’s defense, smashing a wine glass against the table and lunging at her castmate.

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Lisa on ‘The Real Housewives of Beverly Hills.’

Of course, this isn’t the first time the couple — who wed in 1997 and have two daughters, Delilah, 16, and Amelia, 13 — have faced a tough chapter.

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“Marriage takes work, and there’s a reason why we are still together,” Lisa tells ‘Closer.’ Indeed, they’ve supported each other through struggles like substance abuse — Harry quit drinking more than three years ago — and Lisa’s well-documented plastic surgery woes.

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Lisa with Harry on August 25, 2014.

Says a friend, “Harry stuck by Lisa when she really overdid her lips and wasn’t finding work.” Throughout the years, the pair have been vocal about their unwavering loyalty. (Not to mention
their, ahem, chemistry: When asked the secret to their lasting union, Harry told ‘Closer,’ “Great sex!”)

So it’s no wonder, then, that Lisa reacted to Kim’s attack with such fireworks. “I am fiercely protective of my family,” she says. “You mess with my family, you mess with me!”

To read the full story on Lisa and Harry, pick up the new issue of ‘Closer Weekly,’ on newsstands now!