Singer Justin Bieber was spotted cosying up to model and makeup artist Jayde Pierce when they went hiking in Runyon Canyon here.

The two went hiking on Sunday.

The 19-year-old model posted on photo-sharing website Instagram a photograph of her and the "Baby" hitmaker. In the photograph, Pierce is seen with her hands on Bieber's shoulder, reports aceshow.biz.com.

She bared her cleavage in a white crop tank paired with grey training pants. The "Beauty and a beat" singer, meanwhile, sported black snapback and grey t-shirt.

In a video shared by the model on photo-sharing application Snapchat, Bieber went shirtless while walking backward. Pierce could be heard laughing in the video.

In another video, the shirtless Bieber gave the sexy model a piggyback ride. "Yay we made it to the top," the model said in the video.

"He carried me halfway through but that's fine," she added.

The duo was spotted going shopping in Beverly Hills on Saturday.

A fan who later spotted the 21-year-old singer outside a restaurant asked for a photograph, but the singer declined because he said he had to take Pierce "safely" into the waiting car.