In March 2018, 45-year-old Kevin Esterly made headlines when an AMBER Alert was issued for 16-year-old Amy Yu. Esterly and Yu were located almost two weeks later in a Mexican resort town, and according to police, the father of four had been having a “secretive” relationship with Yu, his teenage daughter’s best friend.

TELL DR. PHIL YOUR STORY: Are you involved in a story that has made the headlines?

In an exclusive interview airing Thursday, Esterly’s wife, Stacey, opens up about lies and betrayal by her husband of almost 14 years.

“Do you believe that their relationship is sexual?” Dr. Phil asks.

“I don’t,” she responds, adding that she questioned each of them about that and claims both responded with shock. “There are so many questions. I don’t have proof that they were sexual. I don’t know what happened when they took off. I don’t know what happened between when I found out Kevin had an apartment, and he was away from us and our children at home … In my heart, I don’t want to believe that they were sexual, and I’m hoping that this was just infatuation with him trying to help her as a father figure, and he got sucked into something.”

WATCH: Woman Admits She Was ‘Jealous’ Of Husband’s Relationship With Their Daughter’s 16-Year-Old Friend

In the video above, hear more from Stacey, including why she believes her husband rented an apartment blocks from Amy’s home. And on Thursday, hear what happened when she spoke to her husband for the first time after he was arrested, and what she wants to say to him now. Check here to see where you can watch.

TELL DR. PHIL YOUR STORY: Inappropriate Relationship?

Woman Claims She Tried To Warn Mom Of 16-Year-Old That Daughter Had ‘Inappropriate’ Relationship With Her Husband