In PEOPLE's exclusive sneak peek at Monday's episode of the Bravo series, Lindsay Hubbard tells Paige, 29, that Craig, 32, has been hooking up with Kristin Cavallari. (There were rumors that the duo were seeing each other after they hung out in Nashville together, but they later denied them.)
"I'm trying to be a good friend. She asked me, 'Is Kristin hooking up with Austen or Craig?' And I was like 'Craig,' " Lindsay admits to Southern Charm star Craig in the clip.
"Me and Paige can hook up with whoever. We're all okay with it," he replies, to which Lindsay says, "Oh okay."
Craig then spots Paige walking up the stairs. "Paige what are you doing?" he says, following her up. "If you let Lindsay get in our head, you are weaker than I thought."
"I'm sick of Lindsay getting in my life. Lindsay sucks," he continues, as Lindsay is shown crying in the kitchen.
Upstairs, Paige tells the Southern Charm star, "Craig, now I look stupid."
"No you don't, because of what Lindsay just told you? Why don't you just ask me straight up?" he says.
"We've been having a blast and you know better than this," Craig adds, while newcomer Mya Allen chimes in, "Craig, let her make her own decisions and she's strong, the opposite of weak."
"But this is dumb. Lindsay, who's the biggest loser in the world, her and Austen have been dating for four years while dating other people," he claims, referencing Southern Charm costar Austen Kroll. "They are. You know that. I'm not going to get into this."
"You just said that him and Lindsay have been dating for four years?" asks a shocked Ciara Miller, who had a romance with Austen on Winter House last year.
"He's a loser!" Craig yells, before turning back to Paige. "I'm not going to continue this, you and I are good. I really hate that they upset you, I wouldn't have come here if I'd had known Lindsay would get in your f—--- head. That's absurd."
"He just like gaslit the s— out of you," Mya comments after Craig leaves.
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"I don't think either of us has ever dated someone else in the industry. We get each other, it's nice," he said. "We really are each other's biggest fans, which is something that I've always looked for."
Summer House airs Mondays (9 p.m. ET) on Bravo.