'Teen Mom 2': Leah Messer Opens up About Her First Experience With Sex at 13

Leah Messer is recalling her first time having sex at age 13 as the mother of three figures out how she will navigate teaching her daughters about the birds and the bees. Tuesday's Teen Mom 2 showed Messer celebrating twin daughters Aliannah and Aleeah's 10th birthday as she discussed her own adolescence with friend Kylie.

"I cannot believe my kids are 10. I was 13 the first time I had sex," Messer, also mom to 7-year-old daughter Adalynn, revealed. "The girls are 10. Granted, I did not get pregnant until later. I'm saying it's confusing. I didn't know anything! I didn't know anything." When it comes to sexual education, the reality personality said she wants her daughters to "know everything and know what happens," not just that they don't want to follow in her footsteps of teen pregnancy.

Kylie replied, "But I think your atmosphere growing up was way different than their atmosphere. Yours was obviously not that great, so I don't think that that's something you have to worry about. But you're right, you have to let them know about things. Be honest with them."

Later, Messer told her daughters, "You guys get to learn from my mistakes, right?" with Ali responding, "You've made some big bad mistakes." The Hope, Grace & Faith author clarified, "What do you mean I've made some big bad mistakes? Getting pregnant at 17 wasn't a mistake, it was a challenge. ... I didn't know what the heck I was doing, but I made it work and look at us now."

After opening up in her new book about her battle with substance abuse and mental health struggles, Messer told PopCulture.com last month that she hasn't withheld the details from her daughters. "My girls are getting ready to go into middle school, and there's nothing I would want to hide from them," she explained. "I'm not perfect; they're not going to be perfect. We're all imperfectly perfect. ...Even with addiction, I want them to understand what can happen if they go down that path and how scary it can be." While showing so much of herself to a national audience for years can be difficult at times, the MTV star said it's all been worth it. "If I can use [Teen Mom 2] to make a difference in one person's life, I'm happy," she said. Teen Mom 2 airs Tuesdays at 8 p.m. ET on MTV.