Was Aniston Forced to Make Sophie's Choice?

The buzz is ... John Mayer dumped Jen Aniston. But how to know? Look closely at the photo of Jen at a friend's house in Bev Hills taken yesterday ... see the two dogs on the grassy knoll? They could unlock the mystery.

We're hearing the dogs, especially Norman (the little one) was a John hater, and Jen loves that pooch.

So if she had to choose....