My bf gave me his facebook password and curiosty got the best of me? Should I confront?

..Last night at my boyfriends house, he was going to go out and get us something to eat while I stayed, he asked if I wanted to go online and I said sure, he said I can go on his FB or whatever. I asked Why would I need to go on your FB? He said he has nothing to hide..he doesn't care..an then he told me his password..

and curiosity got the best of me. there were this messages from this girl I guess he messed around with, Im guessing before me. We've been together since October, and he says he love me and all of that but these messages were from dec 15th..h started it by saying "hey sexy" to her and they asked how each other was doing..ad then he tells her that he misses the late night phone calls/texts and pictures from her and then he asks her to call him sometime and she replies she never saved his number that she thinks se may know what number it is and he gives it to her again? that was it.

Im a little hurt by this...just don't know if I should tell him how I feel...I'm a single mother and ive been hurt aa lot..obviously I have trust issues...I love this guy but now Im not sure I can trust him...