Leah's Nightmare! 'Teen Mom 2' Star Messer BREAKS DOWN In Tears Over Special Needs Daughter's 'Decline In Mobility'

Grab the tissues!

In a sneak peek clip for Teen Mom 2, Leah Messer opened up to her friend, Maddy, about her daughter, Ali, using her wheelchair. "It makes her feel so independent," she admitted. "I've been trying to get her to use it as much as possible, but if she doesn't, if she wants to walk, I feel like she should have that option."

Even though Leah admitted to allowing her daughter to have that option, she said that doctors told her when she turns 7-years-old, they could possibly see a "decline in mobility." After her friend asked if she has been noticing any signs, Leah broke down in tears.

Watch the heartbreaking clip above! Teen Mom 2 airs Monday nights at 9pm ET only on MTV!