Justin Bieber and Sofia Richie have reportedly split after dating for a month. Why did their romance come to an end? Apparently, the Sorry hitmaker decided to ''cool things down'' with the model because their romance was "super-hot and heavy".

A source told E! News their romance was "super-hot and heavy". Moreover, the singer "doesn't want a relationship right now, he wanted to cool things down. It wasn't an intentional cool-off. It just sort of happened on its own," the source said.

Another source told the celebrity news website that although the couple were casually "hanging out and having fun" they were "never officially together."

Previously, when Sofia was asked about her status with Bieber, she said: "We have a special relationship. Justin is very easy to talk to, and that's hard to find with people in Los Angeles."

"Besides hooking up it all started as really good friends so they have a great foundation. They have not discussed titles yet with each other, just taking it slow," the source said.

The source continued: "Sofia would like to be exclusive and hopes it will lead into that shortly. She has always had something for Justin."

Bieber and the 18-year-old model were first romantically linked when they were spotted holding hands at Laguna Beach on 5 August. On the morning of 9 August, the younger daughter of legendary singer Lionel Richie was spotted in her pyjamas while waiting for her ride outside Bieber's Toluca Lake home. Moreover, Beiber and Sofia were also pictured kissing and cuddling on board a yacht in Mexico on 8 August.

Justin Bieber
Bieber and Richie were first romantically linked when they were spotted holding hands on 5 August Christopher Polk/Getty Images