Christopher Meloni and Mariska Hargitay have been airtight for more than two decades.

Meloni, 59, and Hargitay, 57, co-starred on “Law & Order: Special Victims Unit” for 12 years, since the show’s premiere in 1999. They will soon reunite for an episode of “SVU”, which will set up the Meloni-led spinoff “Law & Order: Organized Crime”.

Meloni left the show in 2011 after contract negotiations broke down. Hargitay tells People she was “devastated” by her co-star’s abrupt departure.

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“She was left in the familiarity of what we were,” Meloni adds, “but for me it was about how things fell out – and the word I’ll use is that it was ‘inelegant’. At the end of the day, how it was handled was, ‘Okay, see you later.’ So I went, ‘That’s fine.'”

When asked what lured him back to star in his own spinoff, Meloni replies: “That’s personal and complicated.”

Meloni also dishes on how his detective mind was tingling when he saw Hargitay interact with her now-husband Peter Hermann on the “SVU” set.

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“He’s on the show as a guest actor, and I’m looking at her, looking at him, and I’m seeing how she’s acting, right?” Meloni explains. “I know her, and I’m like, ‘Oh boy. Here we go.’ Later, after dating, Hargitay came to Meloni declaring, ‘I don’t think it’s going to work.’”

“The whole time the [thought] bubble in my head was just: ‘You’ll be married within five months.’ That’s all I was thinking,” he adds. “I knew. I knew.”

“Law & Order: Organized Crime” premieres April 1. The new issue of People is available on newsstands Friday.