The ex-girlfriend of One Direction's Niall Horan has admitted that his stint on The X Factor was what split up their relationship.

The pair, who met when they were just 13-years-old, dated for around 9 months but their romance was short-lived after Horan's involvement in the televised vocal talent show.

Speaking to Now magazine, Holly Scally explained that trying to keep in touch and find time for each other during his time as a contestant on The X Factor was nearly impossible so they decided to call it a day as a couple:

"We were apart for four weeks, which felt really long because we used 
to see each other all the time. One day Niall called and said: "I think we should finish because I never see you. I said, "Yeah, I know. 
I understand". So it's cool."

"I think he felt bad because he kept saying, "I'm so sorry". I tried to sound like it was no big deal, but it was a bit sad for me. I liked him more than I'd let on. I missed him, but we still talked on Skype and we met up whenever he was back."