I have to speak from some experience on this subject here:

My BF and I, not to long ago, had this same situation. He had a good friend that he talked to on a regular basis that I knew about. One night, just fidgeting around, I find a text message on his phone to this chick that says "Call me when you are not busy and no one is around. I really need to talk to you badly" Then he ends this text message with some pathetic little typed picture of a rose (i.e. ---/---<@) Anyway, I tried to put this out of my head and that worked for about 10 minutes. I was just burning inside wanting to know what was up with this text message. So I confronted him and he, of course, said it was nothing and that I was making a "mountain out of a mole hill". Whatever - that still wasn't good enough for me.

I finally came to the following conclusion and told him that he either accept this one or live without me. I made a deal with him that I could play and snoop on his phone whenever I got ready (I mean, if he is not hiding anything then what's the big deal). I told him that I wanted to continue to be able to do this checking until I felt comfortable about the situation. He agreed and I checked a few times and saw nothing out of the ordinary, its been happy living ever since.

Good luck and hang in there - but also know when to call buddy if she is really messing around.

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Would you like more sex with that?

I wouldn't recommend sex, drugs or insanity for everyone, but they've always worked for me.