Sandler, Aniston barely beat Bieber at box office

Adam Sandler and Jennifer Aniston are America's box-office sweethearts, but Justin Bieber is the valentine for teen fans.

The Valentine's Day weekend was a close one as Sandler and Aniston's romantic comedy "Just Go With It" debuted with $31 million.

That was just ahead of the concert documentary "Justin Bieber: Never Say Never," which opened a close second with $30.3 million.

The teen pop idol's film …