PETALING JAYA, May 16 — South Korean singer Ailee has opened up about a cheating ex-boyfriend and how the incident went on to impact another relationship.

The powerhouse vocalist recently appeared on the South Korean talk show Video Star where host Kim Sook asked for the story behind her song If You.

"I heard that there’s a song Ailee sang while thinking of an ex-boyfriend who cheated on her,” said Kim, based on translations from Soompi.

Ailee responded by saying the song was not directed towards her unfaithful ex-lover but to a boyfriend who had to pay the price for a mistake he didn’t make.

"I didn’t treat him well. I found that I couldn’t give all my heart to him because my ex-boyfriend cheated on me.

"I drew a line between us,” she confessed.

The Heaven singer then revealed how she caught her ex-boyfriend with another woman at his birthday party after telling him she wouldn’t be able to attend due to schoolwork.

She secretly turned up anyway and got a nasty shock when she found him in someone else’s arms.

"I popped in as a surprise, and the people there scattered like cockroaches. I saw my boyfriend being physically affectionate with another woman.

"I was so shocked that I couldn’t say anything.”

Ailee said she "went home crying” after the incident and that the painful memory of her ex-boyfriend lingered on long enough to affect another relationship, giving her the inspiration to pen the lyrics for If You.

In the song, Ailee sings, "Because of my past breakups, / Because of my scarred memories, / I was afraid to give you my all.”

Video Star host and former 2NE1 member Sandara Park then asked if Ailee, whose real name is Amy Lee, had a message for the ex-boyfriend who cheated on her.

Unlike most stories where infidelity is involved, Ailee’s one has a peaceful ending.

"We’re friends now. (The relationship) ended with strong cursing at the time, but we made up and are friends,” she said with a laugh.