Sites for Hacking a Facebook Account

I think that my girlfriend has been talking to her ex-boyfriend again, and I need to find out if this is the case. I know that she recently ran into him, in a grocery store. But she said that nothing came of it. I do not know if that is the truth, and I am worried that she might leave me, for him. But she has a crazy mixed up past with the guy, and I don’t think he is good for her. I am looking to use a site to hack facebook account of my girlfriend, and to see if she has been talking to him on Facebook.

I know that they are still friends on Facebook, and I have tried to get her to remove him as a friend.