'Teen Mom OG' Sneak Peek: Catelynn And Tyler Get Emotional Before Saying 'I Do'

The bride and groom share some heartfelt moments with their loved ones on their special day.

Catelynn and Tyler have shared so much together during their 10-plus years as a couple -- and during this week's episode of "Teen Mom OG," the high school sweethearts will take the next step in their love story and become husband and wife.

In a sneak peek from the special 90-minute installment below, the young parents -- who chronicled their engagement(s), bachelor/bachelorette party and festivities leading up to this milestone on the long-running series -- share some emotional moments with their family before meeting at the altar. For starters, Ty and his father Butch -- who is newly free from a lengthy prison sentence -- reflect on their troubling past and what this occasion means to both of them.

"I missed your graduation by one day -- I was feeling like a really bad father," a teary Butch tells his child. "I mean, I'm already a bad father, but that much worse. I can't tell you how happy I am. You ain't seen nothing but good coming out of this guy."

How does Ty react to the patriarch's heartfelt words? Watch the entire touching exchange in the clip -- plus see Cate's adorable moment with her brother Nick -- and don't miss "Teen Mom OG" on Monday at 10/9c!