Teen Mom’s Leah Messer Is Engaged to Jaylan Mobley: ‘I Couldn’t Imagine Myself Being

Leah Messer is ready for an exciting new chapter in her love life!

The longtime Teen Mom cast member’s boyfriend Jaylan Mobley proposed to her on Friday night. The romantic moment occurred during their anniversary trip to Costa Rica, where Mobley asked for Messer’s hand in marriage while taking a romantic stroll on the beach after the couple enjoyed a dinner prepared by a private chef.

Mobley popped the question with a 4.7-carat custom ring designed by jeweler Mike Nekta of New York Diamond Jewelry.

Speaking exclusively to PEOPLE about her engagement, Messer says, “It feels amazing. I never imagined myself being here today, but I couldn’t imagine myself being anywhere else,” as Mobley adds, “I can’t even express how I’m feeling. I wanted this moment to be the perfect moment for her.”

Though Messer says she “knew something was going on” ahead of Mobley’s proposal, she explains that she “had no idea it was going to be like this.”

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When it came time for him to propose, Mobley tells PEOPLE he was “nervous” but prepared at the same time. “I’ve been thinking about this for at least 2-3 months,” he says. “I knew that it would be cool if we did it in Costa Rica — where we came when we first started dating.”

He adds: “A lot of people helped pull this off. I just consider myself to be blessed and lucky to be in her life.”

Once Messer and Mobley return home from their romantic getaway, the pair plan to tell the reality star’s children about the engagement together. “The girls have been asking if I plan to propose, [and] I think the best way to tell the girls is for us to do it together. I have a surprise for them as well,” Mobley says.

Messer shares daughter Adalynn Faith, 9, with ex-husband Jeremy Calvert. She also shares 12-year-old twin daughters Aliannah Hope and Aleeah Grace with ex-husband Corey Simms. (The MTV star was married to Calvert from 2012 to 2015, and Simms from 2010 to 2011.)

Messer tells PEOPLE that her girls see Mobley “as a role model,” as well “as another father figure in their lives.” She adds: “They have a great relationship.”

Messer made her relationship with Mobley Instagram-official in September 2021, sharing a PDA-filled snap. Now, as she prepares to head down the aisle again, she tells PEOPLE what the duo envisions for their big day.

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“I want to walk myself down the aisle,” Messer says. “I say this over and over again. I’ve made it to where I am as a woman and a mom, and I want everyone to see that strength.”

Looking ahead to the next chapter in their lives, Mobley notes, “I don’t know if I can say that there’s one thing [I’m most excited about].”

“I’m just looking forward to everything that we’re going to do together — making this commitment to each other, making a commitment to the girls, growing our family, and just doing this life together as one,” he adds.

As for Messer, she says, “I’m looking forward to everything that the future has in store for us — our families coming together, the kids we’ll bring into this world together, growing businesses together.”

“It’s very open,” she continues, “but I’m excited about it all.”

Messer can next be seen in Teen Mom: The Next Chapter, premiering Sept. 6 at 8 p.m. ET on MTV.