Tom Schwartz came clean about when exactly he found out about that months-long Tom Sandoval and Raquel Leviss affair during an appearance on Wednesday’s “Watch What Happens Live”.

Schwartz told Andy Cohen that he knew about what he assumed was just going to be a one-night stand back in August, but it wasn’t until January that Sandoval told him how he really felt about Leviss.

“Vanderpump Rules” stars Sandoval and Leviss hit headlines last month after their affair was revealed. Sandoval had been dating Ariana Madix for nine years when she found a NSFW video of Leviss on his phone. They’ve since broken up.

READ MORE: Lala Kent Claims Ariana Madix Lost Weight Following Tom Sandoval Cheating Scandal

Schwartz told Cohen, “In January, Tom came to me… and he told me that he was in love with Raquel… I was flabbergasted.”

After Sandoval told him about the affair, he said the cheating scandal then became “an open secret.”

“After that, Tom kind of got flagrant — he was brazen,” he said.

Schwartz recalled how their one-night stand turned into an “emotional affair” in the fall.

He said, “I learned in August, in late August about the affair, the one-night stand — allegedly,” insisting: “Tom was having, like, a midlife crisis.”

The reality TV star continued, “From my point of view, it became, like, an emotional affair — which is still inappropriate.”

Cohen questioned Schwartz on why he didn’t tell Madix considering she’d been such a good friend to him. However, Schwartz said his longtime friend and business partner Sandoval had fed him the “narrative that he has broken up with Ariana, or attempted to multiple times — many, many times. And he’s not happy, they’re not healthy, they’re not intimate, blah blah blah.”

Schwartz went on, “He did a good job of placating me. … And he told me he has a game plan, he’s gonna do the right thing — and then he just kind of continued to procrastinate.”

READ MORE: Scheana Shay Breaks Silence About That Fight With Raquel Leviss After Tom Sandoval Affair Reveal: ‘I Did Not Punch Her’

When questioned whether he was mad at Leviss elsewhere in the chat, Schwartz admitted, “I’m more upset with Sandoval because he took advantage of my kindness. And he put a lot of people, not just myself, in very compromising situations where our integrity was at stake.”

Schwartz also said Sandoval was “addicted” to Leviss, calling her his “heroin.”

He said because Sandoval has ADHD, he “became obsessed” with Leviss, adding: “He’s addicted. It’s an infatuation of all infatuations.”