"Modern Family" actress Sarah Hyland and ex boyfriend Matt Prokop had a shocking break up earlier this month after five years of dating. New reports suggest that since the break up, Matt Prokop has become "obsessed" with Sarah Hyland and won't stop trying to call and text her, tempting her to seek legal action.

According to Classicalite, an insider told Star Magazine for the September 29 issue that Matt Prokop's behavior since their break up is getting so upsetting that Sarah Hyland may be forced to take legal action.

"Matt has become obsessed with Sarah.

"He calls and texts her constantly and has even said some strange things about her and her dog.

"She's terrified and wants [him to] stop."

The "Modern Family" actress and ex boyfriend Matt Prokop lived together and started dating in 2008 when they met during their audition for "High School Musical 3." They then starred in the film "Geek Charming" in 2011.

"She's young. They decided they would be better off as friends." Sarah's rep said after reports of their break up became public, Travelers Today reports.

Perhaps Sarah and Matt's relationship became very serious too early on in their lives. When Hyland turned 23 on last year, she debunked rumors that she and Matt were thinking of getting engaged.

"There have also been things in the paper - The Enquirer - that we're engaged and 'Julie Bowen does not approve,' which is not - any of that - is all false. It's all fictitious," she told E! News at the Hollywood Foreign Press Association & InStyle's 2014 Golden Globe Awards Season kickoff party in November.

"I'm about to be 23, I turn 23 on Sunday, and I never really saw myself getting married at a young age like that, which I think is young," the TV star continued.

"So we've been together a long time, we're practically married. We have a dog and live together, so I'm OK with that."

"Modern Family" season 6 premieres this Wednesday, September 24 at 9pm on ABC.