Hi i am in a relationship with this girl and the other day i noticed as she was on her facebook profile she thot i was asleep but i got a glimps of an inbox message in her account from another guy and i think they were talking about sex and meeting up, i didnt get much time coz she then noticed i was awake. is there a way i can get into her account and see the inbox messages. she opened the account from her cell phone and only checks from the cell phone. i know her login id is her cell number but thats it. I really need to be sure that she is not cheating on me can anyone help me please is this possible.

Please help.