Teen Mom: Mackenzie McKee Realizes It's Time for the Sex Talk with Son Gannon, 13, After Reading Texts with His Friends

Mackenzie McKee has a teenager on her hands.

The Thursday, Feb. 13 episode of Teen Mom: The Next Chapter shows the mom of three, 30, celebrating her oldest as her son Gannon turns 13. McKee is also mom to Broncs, 8, and Jaxie, 11.

Throughout the episode, the mom notices the changes in her little boy. Gannon leans on her fiancé, Khesanio Hall, as he prepares to go to his first school dance. Whenever McKee chimes in, the teen groans and opposes her involvement. McKee even learns that Khesanio found out about Gannon's first crush before she did.

It all comes to a head at the end of the episode, when the couple is in their kitchen and Gannon's phone goes off in his backpack. The curious mom picks up the phone and starts to take a peek, though Khesanio tells her she shouldn't.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories.

"I don't think that's right," he advises. "Leave his phone alone. How would you feel if your mom searched your phone?"

"She did, all the time," McKee says of late mom Angie Douthit.

The mom's eyes go wide as she scrolls. When Khesanio looks over, his eyebrows go up. Neither says a word at first, then his jaw drops as he says, "Oh."

"Did you talk like that when you were a kid?" McKee quietly asks him, to which he reassures her he did.

"It feels like I don't know who this kid is though," McKee says.

In a confessional, McKee says, "When I close my eyes and think about what I was doing behind my mom's back at the age 13..." and takes a deep breath.

"His friends are talking about getting ----jobs. Gannon knows about these things and he's talking about them. Has he done any of these things? I don't know. But my parents, they didn't talk about sex and there would have been a way different outcome if they did," she says.

"So I know I need to take a different approach with my kids. I mean, you just lose so much control with teenagers. You lose so much control of what they're doing because they're going to do it. You can keep them at home in a bubble and they're going to figure a way out."

Teen Mom: The Next Chapter airs on Thursdays at 8 p.m. ET on MTV.