Sneak Peek! 'Teen Mom OG' Stars Catelynn Lowell & Tyler Baltierra Reunite Long-Lost Sisters In 'Reunited' Clip

The first reunion!

In a sneak peek for Reunited, Catelynn Lowell and Tyler Baltierra reunite two long long sisters, and even bring their mother in. "So we met up with your sister yesterday, and she's here and she wants to meet you," Tyler tells Kati of her sister, Hazel.

"What is going through your head right now?" he asked Kati, who replied with tears in her eyes, "I get to see my sister!" Catelynn stepped in to warn her about some things that "might be hard to hear."

Watch the emotional reunion between the sisters in the clip below! Reunited airs Monday night at 10pm ET on MTV!