A missing teen from Allentown, Pennsylvania was found in Mexico with her best friend's dad. While the 16-year-old girl, Amy Yu, has since returned home, the news isn't as good for the 45-year-old man she was with.

ABC 6 reports that Kevin Esterly was arraigned in court on Sunday and is currently being held in Lehigh County Prison. His bail was set at $500,000. Esterly has been charged with interference of custody of a child. 

Yu originally went missing on March 7. Shortly after, local law enforcement were notified that Esterly had purchased one-way plane tickets from Philadelphia to Cancun. Following an Amber Alert issued by the Mexican federal government on March 16, she was found by authorities in Playa del Carmen the following day.

Esterly has known Yu since she was seven years old, reports local paper the Morning Call. The Esterly family often included Yu in their family vacations and considered her their "fifth daughter". 

Yu and Esterly were involved in a romantic relationship, and he often signed Yu out of school without her parents' knowledge. Esterly's wife, Stacey, confronted her husband about the relationship and reportedly has not been returning his calls from prison.