Rumor Mill: Ryan Cabrera & Riley Keough Split?

Did an ex put an end to Ryan Cabrera and Riley Keough's relationship?

The couple of two years reportedly got into a heated argument on Friday when Riley caught her beau red-handed with his ex-girlfriend at his album release afterparty at Hollywood's Play nightclub, a source tells OK!.

"At the end of the night, Riley searched all throughout the crowd and headed back to the bathrooms for Ryan," the source tells OK!. "The women's bathroom was locked, but she heard Ryan in there and so she forced the door open and saw Ryan in the bathroom with his ex-girlfriend from Texas."

Upon discovering them, the 18-year-old model "cried and yelled" before leaving. Ryan, 25, though, never followed suit.

"He stayed at Play for about 20 more minutes, flirting with his ex, then he went home and drove his car to the airport. He took a 6am flight out to Texas to go on tour and left Riley in California," the source adds.

However, a rep for Riley denies the report.

"This is not true," she tells OK!.

By Joyce Eng