Me and my girlfriend have been together for five years, and lived together for two. We've always been very open with each other, I know her ATM-cards PIN code, her email password, her work password, she's never been void of me using her computer and phone etc..
A couple of months ago, I started to realize a change. She started using the computer a lot more, and definitely started becoming more secretive about what she did. She often went to the bedroom to write SMS messages, and when I asked what she was doing in there for so long, she simply answered "I was just answering a text message".
I got curious, and since I'm a CS major, the first thought I had was to retrieve the contents of her email. I noticed a lot of messages from a guy named Michael Wilson. But nothing really out of the ordinary, just random chatter about work related stuff and movies and that sort of thing.
Either way, it arroused my suspicion, because she usually talks about all the people she works with, male and female.
So I went one step further, and put up a script that sent me her IM history once per day.
One conversation they talked about "this upcoming Friday, Alice is having a movie night". And she asked if he wanted to come along. He replied that he probably would stop by. She had not said a word about this to me, so I very casually asked if she had any plans for the weekend. She then replied that she was going to Alice for a movie night, but probably not a movie I'd be interested in. I replied that I had no other plans, so I could very much come along if she wanted to. She said OK.
When we then got into bed, she was awfully quiet, and said that sometimes, she simply wanted to do something with the girls, without me there.
That's fine by me, I said. I'll find something else to do.
The next day, she had changed her mind, and wanted me to tag along. Finally, I would meet this mystery character "Michael". When we got there, though, there was no Michael. And no-one mentioned that he couldn't come or anything like that.
So I checked the previous logs from IM, and realized that my girlfriend had written "Oh, my boyfriend will be there, by the way" in a chat. But Michael hadn't replied.
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Now I'm really suspicious, so I setup a Remote Desktop connection to her computer, so that I can monitor what she does. One password I've never had is her Facebook password, so that's the main point of this remote desktop connection. Then I can see what she writes in real time, and how she writes.
As I was afraid of, she rewrites her sentences alot when writing to Michael, afraid of being misinterpreted.
Michael often teases her in a "flirty" kind of way, but she never replies in the same fashion. Although, one time she wrote something in the realms of "You always have so many negative (the flirty kind referenced in the previous sentence) things to say about me. What are the positive?"
She never got an answer about that, so one time I caught her almost sending "I'm waiting for that list of positive things!", but then deleting it.
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Anyways, yesterday, I got really annoyed.
Over the weekend, they have a short day at work (she's already told me about it), and so do I. I cought her replying to Michael, "By the way, do you want to go see Shutter Island on Monday after work?", and then adding "or maybe Valentines day?", and then quickly removing the last part from the message. She sent the message, and quickly got an answer "Sure!".
Since I'd already seen the movie, I thought maybe that's why she didn't want to ask me. But seeing as I love the movie, a bit later in the evening I watched the trailer for the new Leo-movie, Inception. I also said, "Man, Leonardo sure can act. Oh, you haven't seen Shutter Island yet. Maybe we can go to the movies and see it together? I'd love to see it again.".
She simply replied "Yeah, maybe we can.", and when I followed up with "What time is good for you?", she said "We'll just see."
She went to bed early that night.
Any tips, hints? How should I deal with this? I really don't think she's actually cheating on me – yet, but she is way more distant, she always deletes her browser history and never leaves her phone lying around anymore.