Teen Moms Reveal What Shocks Them the Most About Costars' Kids as They Turn 16 (Exclusive)

The new season of Teen Mom: The Next Chapter is super sweet -- Maci Bookout, Leah Messer, and Amber Portwood's children are all turning 16, the same age the stars themselves were when they made their reality TV debut on 16 and Pregnant. In an interview with TooFab, Maci, Leah, and Catelynn Lowell reflected on the "full circle" moments of seeing the kids all grown up and celebrating their milestone 16th birthdays. The new episodes feature Teen Mom marking the MTV reality franchise's 16-year anniversary. Fans will feel nostalgic -- and maybe a little old -- knowing that Maci's son Bentley, Leah's twin daughters Ali and Aleeah, Amber's daughter, Leah, and more of the Teen Mom kids are turning the big 1-6. While Leah's twins won't be officially be celebrating their birthday until later this year, viewers will get to see Bentley's birthday festivities and Leah even being gifted a car! "I think what makes me feel old is just seeing all the OG babies turning 16, like Bentley and Leah, because I remember when they were just little babies and I'd be in the back green rooms wanting to snuggle them all and rock them to sleep and feed them," Catelynn said. "I was like, 'I'll be the mom. Just give them to me, you know?' So that's crazy." Catelynn -- who welcomed daughter Carly, 15, with husband Tyler Baltierra, before making the difficult decision to put her up for adoption -- added that she recently saw Maci's son Bentley and couldn't believe how much he's grown. "We saw Bentley this weekend, and he's so tall, and every time I see him I'm like, 'You are so big!' It's just, it's crazy," she continued, before Maci -- who shares Bentley with ex Ryan Edwards -- recalled Catelynn's reaction. "She said, 'I went to go hug him, and I'm like, "Why are you so big? ... You're supposed to be a little Bentley still!"' Maci shared similar sentiments, recalling what it was like to see her son with Leah's twins and Amber's daughter, Leah, as they promoted the new season of Teen Mom: The Next Chapter. See the adorable photo, below, which was shared by a fan account. "It's honestly, just literally just seeing, especially this week, seeing Leah, and then Ali and Aleeah," she told TooFab. "I know how I feel like when I see Bentley, and I'm like, 'Wait, yesterday you passed through this hallway, and you were to this part. You went to sleep, and you woke up and now you're to this part.' But seeing them, I'm like, 'Oh my gosh. They are all really, you know, young women." "They're such great kids," Maci added. "And so fun to be around. It was a blast." Leah echoed her costars, sharing that it was a "full circle moment" watching her kids, Bentley and Leah -- whom Amber shares with ex Gary Shirley -- all together, with Maci adding that she was "in awe watching the four of them." After Maci said the girls and Bentley are "so pretty," Leah jokingly added, "and handsome," referring to Bentley. "Don't forget, don't say cute," she said with a laugh, to which Catelynn shared, "Poor Bentley's always being the only boy." To see more from TooFab's conversation with the Teen Mom cast, check out the posts, below! Teen Mom: The Next Chapter premieres on Thursday, January 30 at 8 p.m. ET/PT on MTV.