Melissa McCarthy shows up to Law and Order: SVU set disguised as old woman to surprise Mariska Hargitay

Melissa McCarthy appeared as a guest star on Thursday’s episode of Law and Order: SVU but, funny enough, Mariska Hargitay had no idea she was cast until the day of filming.

McCarthy shared a behind-the-scenes video of herself surprising Hargitay by dressing up as an old lady to sneak onto set. The Bridesmaids star wore a latex mask with a gray, curly-haired wig and oversized coat to secretly enter the location where the episode was shooting.

She then changed into her character’s costume — an all-black fringed ensemble with a gold belt and short black mullet-style wig.

“Holy mother of christ! Are you f—ing kidding me?! Jesus. Oh my God,” Hargitay excitedly screams at McCarthy when she realizes she’ll be playing a guest character. “I can’t believe this! I can’t believe it. I can’t believe it.”

In her Instagram video, McCarthy tells Hargitay that she’s “so hard to trick” before the pair hug and Hargitay insists to the crew, “This changes all the dialogue!”

On the latest episode of the long-running show, McCarthy played pro fighter, Jasmyn Jewell, who flirts with Hargitay’s NYPD captain Olivia Benson as she questions her about a murder victim at a fan expo.

“Sometimes you just have to show up to give a proper ATTA GIRL to a total (ultimate) boss lady ⭐️ Turns out it is VERY hard trying to keep secrets from @therealmariskahargitay on her set but we managed to pull it off and in a world where things are heavy and dark but this day was PURE JOY 🥹🎉💓,” McCarthy wrote alongside the video.

She continued, “Mariska, you are the real deal. Sorry everyone lied to you, hope it was worth it (this surprise was six years in the making people)!!! PS LOOK MA I FINALLY MADE IT ON LAW & ORDER 👮🏻!!!!!”

As the video concludes, Hargitay handcuffs McCarthy, who states, “I’ve been thinking about this for years.”

“WORTH THE WAIT,” Hargitay commented on McCarthy’s post, adding, “Happy feet.”

She also shared her own post on Instagram, which included a photo of the pair on set. “SURPRISE!!!!🫨🤯😲💃🏻💃🏻 #MELISKA mind blown and still doing the happy dance! 🥰🥳”