Selena Gomez may have a largely sweet image, but she is also a pro who does not take BS from interviewers.

Bottom line: She doesn't take kindly to being asked about her ex Justin Bieber in interviews. While she was fine with discussing the subject with Ryan Seacrest on Sunday night's E! special, it was likely a pre-approved question. When interviewer Dean Richards deigned to ask Sel about The Biebs during an interview yesterday (July 22), she promptly hung up on him. Ouch!

Gomez phoned in for the chat via satellite and was not prepared for Biebs-related questions, since her PR team likely briefs reporters on what's acceptable and what isn't when it comes to questioning. We're going to assume that anything about Bieber is on the "Do not ask" list.

Still, Richards asked, "You're, you know, probably as close a friend to Justin Bieber as they come. Is there something about him that we don't get or we don't understand?" He pushed further, saying, "I mean, there is one story after another of, you know, pretty outrageous behavior that we're reading about."

Those questions have nothing to do with Selena's new album 'Stars Dance,' out today, July 23. So we can understand why she may have been miffed. Then again, of course people want to know about her high profile ex.

Gomez was probably prepped for softball, promo-only questions and was blindsided by a Bieber interrogation so she bailed on the interview. She didn't even attempt to answer his queries and promptly hung up.

You know, yesterday was her 21st birthday and she was working. Who needs to be badgered about her personal life when she has a new album out? While Gomez's fame did rocket into the stratosphere after she hooked up with Da Biebs, we are firmly Team Selena on this sitch. A working girl cannot be solely defined by her ex!