Selena Gomez ran into a pal's apartment building on Saturday night wearing what looked like pajama pants with heels, and when asked whether Justin Bieber was the reason why she completed a quickie stint in rehab last month, she ducked her head and declined to answer.

The former Disney darling checked in to The Meadows facility in Arizona on January 5, and though there were some reports that she was "exhausted" and "broken hearted" following her split from Bieber, several other websites claimed she was smoking marijuana and dabbling with prescription drugs Xanax and Ambien.

"Selena came to understand just what a bad influence Justin had been on her life. Their relationship left her broken-hearted," a source told Radar. "I don't know whether Justin pushed her to drug use, but amongst their close knit group of friends, smoking was common place."

In other news, Justin has changed his Instagram name to Bizzle, and he posted the below pic last night from the studio in Atlanta. Hey, if he's working on music, he's probably not getting into as much trouble, right?

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