'Summer House' 's Carl Declares 'There's No Rules' as He Leans into 'Fast' Proposal to Lindsay: 'Feels Right'

For Kyle Cooke's 40th birthday, he received some unexpected news.

On Monday's episode of Summer House, Carl Radke told Kyle that at the end of summer, he planned to propose to girlfriend Lindsay Hubbard after less than one year of dating.

"That's like, within a month," Kyle pointed out.

Carl, 38, told Kyle he hadn't talked to Lindsay's dad yet or picked up the ring, but he had picked one out. "I'm excited for you guys," the Loverboy founder said.

In a confessional interview, Carl acknowledged that his decision to propose may be viewed as a hasty one.

"There's no playbook," he said. "There's no rules about when you're supposed to get engaged. I'm just going for what feels right in my heart. This is the biggest decision I'll ever make in my life. I just know that I'm happy. I'm in love. I want to take this next step with my best friend. Is it quick? Maybe, but I see a future here, and I want to make that more official."

Carl conceded as much to Kyle, telling him that while his and Lindsay's relationship has moved "fast," he'd also "known her so long."

Kyle proceeded to get ready for his 40th birthday hoedown. According to his wife and costar Amanda Batula, Kyle had grown out his now-infamous mullet for the occasion.

"Kyle's 2020 New Year's resolution was to grow a mullet for his 40th birthday," the 31-year-old told the cameras. "And now that were here, I'm hoping that, you know, part of his growing up and maturity will be to cut it."

Winter House stars Jason Cameron and Rachel Clark showed up for the party, and Lindsay, 36, wanted to avoid Jason, 35. (The prior summer, Lindsay experienced a pregnancy loss after finding out she was pregnant with Jason's baby.)

"He needs to steer very clear," Lindsay told Carl.

Carl relayed the message to Jason. "Just want to give you the heads up, I know Lindsay is a little frustrated with not really knowing you were coming," the Syracuse University alum told Jason. "She may not be trying to interact much."

Jason found that "completely understandable."

With the party in full swing, Paige DeSorbo and Craig Conover decided to have a poolside discussion about their relationship after the Southern Charm star talked about it with Carl, Kyle and Mya Allen's boyfriend Oliver.

Craig, 34, pointed out that he and Paige had been "dating for a very similar amount of time" as Lindsay and Carl, but didn't feel ready to take the next step in their relationship like them.

"I was like, 'We've never talked about the middle chapters, right?'" Craig told Paige, recalling his earlier conversation with the guys. "We've always just been like, 'Yeah, one day we'll live together somewhere.'"

Paige laid out her timeline. "We've been dating for a year," she began. "And I'm about to turn 30, I've always thought that like, I was going to be engaged by the time I'm 30. But now that I'm turning 30, I don't want that. Like, we would date another year before you even propose."

"I'm happy right now, and I'm happy doing this for the next year," Craig replied. "But like, when would you even be ready to move to Charleston? Because we haven't talked about this."

While Craig said proposing wouldn't necessitate moving, Paige felt it would launch the countdown.

"If you were to propose to me tomorrow, it would be amazing, but then it would immediately start the clock of like, 'Okay, when are you moving down? When are you planning your wedding?'" she said. "If you propose right now at this f---ing hoedown with a piece of hay, I would say yes, but it's a lot. I will be changing my whole life."

Paige lamented to Craig how she'd be "changing a lot more than you will be" by relocating.

"I have no friends in Charleston," the fashion contributor said. "I don't know anyone. My whole career is there. My family's in New York. I don't want to lose my mom."

To quell Paige's tears, Craig suggested moving to New York City. "If it was for you, I would," he said. "When you are ready to settle down."

To break up the party, Kyle decided to give a revealing speech. "I was like, I'm going to give a speech and I'm going to do it in as few clothes as possible because I'm a humble 40-year-old man," Kyle said before flashing the attendees.

Paige then proceeded to tell Amanda and Ciara Miller that "the thought of like getting engaged and getting married and being someone's wife is very f---ing scary."

The tension between Lindsay and Danielle Olivera continued to escalate during the party, too. The ladies sat down to talk about what Danielle, 34, said about Lindsay and Carl's relationship at a girls' night dinner the previous weekend.

"If you really care about our friendship, you're not going to go tell everyone else around me how you feel. You're gonna come to me," Lindsay said. "I'm finding out in so many other ways how you feel other than by you."

Danielle expressed that she felt like Lindsay hadn't checked in with her lately.

"I don't feel like you hear me or we have equal partnership in this friendship," the entrepreneur said. "Lindsay, our relationship has always been me being there for you."

"And I was never there for you ever?" Lindsay wondered.

Danielle replied, "You never had to be."

Lindsay told Danielle that if she had "an opinion about your relationship with Robert, I would be a little bit more respectful about that than attacking me in a group setting."

Danielle said she didn't view it as an attack on Lindsay, and that the publicist would have a better idea of what was going on in her life if Lindsay ever checked in with her.

"I love you so much and I'm sorry," Lindsay said.

Summer House airs Mondays at 9 p.m. ET on Bravo.