'Unexpected': Hailey Learns Matthew Left Her for Her Best Friend a Week After Giving Birth (Exclusive)

Hailey Tomlinson may have suspected something was going on between boyfriend Matthew Blevins and [...]

Hailey Tomlinson may have suspected something was going on between boyfriend Matthew Blevins and best friend Hailey Tilford before they welcomed daughter Kinsley, but finding out on social media that the father of her child had left her for her friend just a week after giving birth was a devastating blow to her whole family. In a PopCulture.com exclusive sneak peek of Sunday's all-new episode of the TLC reality show, Hailey and mom Tanya try to process the betrayal in a tough-to-watch moment.

Sitting in bed recovering from becoming a mother, Hailey calls her mom into the room to show her a picture of Matthew and "Hailey 2" mugging for the camera on Instagram, announcing they were together.

"She's supposed to be my best friend, but she turns around and messes with my baby's father," Hailey says, shocked. "She's flirted with him before, but I didn't think he was gonna do anything a week after I just gave birth."

Tanya was absolutely livid to see her daughter disrespected like that. "Hailey, I told you I didn't trust her, from that last situation," she fumes. "She was too happy to get over here all the time. She was doing all this to get close to Matthew. She succeeded."

To the camera she continues, "I had a gut feeling from the beginning that Hailey, she was just too friendly with Matthew. No shock that it's her but I'm very shocked that Matthew just upped and left Hailey. I thought he was madly in love with my daughter. I really did. Never did I expect him to take off with Hailey's friend, you know, a week after Kinsley was born."

Breaking down in tears, Tanya admits she is also feeling the sting from the father of her grandchild.

"I feel betrayed by Matthew for what he's done to Hailey," she says, finding it hard to get her words out. "I just pretty much raised him for two years. He was pretty much like a son to me, 'cause he didn't have anybody."

Tanya keeps a brave face in front of her daughter, however, advising her, "I hope you're done. Now you know who he is. Once a dog always a dog. You deserve so much better. His ways, the way he talks to you. He is toxic. He comes from a really bad situation and he was just dragging you down. You're better than that, honey. And she's not."

Hailey wonders, "I'm just confused on what's going through his head and how do you throw two years away for a girl that's not gonna love you?" but her mom is far from worried about Matthew finding love at this point.

"I'm done with him," she states. "He's gonna see the worst of me. You know how mommy's so sweet? Not anymore. It's over. ...For him to walk out on Hailey and his child, it's just really got me upset. I'm not gonna tolerate his behavior. So he is gonna pay the consequences."

Unexpected airs Sundays at 10 p.m. ET on TLC.

Photo credit: TLC