<human>: Can you condense the text into three sentences or less?

After 3 and a half years of going out, I proposed to my GF whilst on holiday. She said yes. 2 weeks later, I found that she had been sending and recieving pictures to one of her old Uni friends. I was devestated, but she assured me that it had stopped and that she was just unsure of herself as I am the only man she had been with and there was a part of her that always wondered what other things could be like.

She told me that she loves me more than anything and after long talks and much crying on both sides, I agreed to stay together on the condition that she break off contact with him. She agreed.

At this point, I'd like to say that I have never met this good friend of hers in the whole of our relationship, and that has always given me suspitions and I've told my GF this. There have been lies told in the past about how much she spoke to him and there's always been a convieniant excuse about why I've never met him.

I have now found out that she sent him a message along the lines of "Things have gone all wrong here and the only way to fix it is to stop talking to you" He replied with "Do what you need to"

This has caused a massive trust issue for me as I am a natural introvert and she is really not the kind of person you would expect this from. I was caught completly off guard.

This morning I found myself checking her phone purely to put myself at ease and I found that he has continued to send her pictures of random things over the holidays, and a single intimate one. I cannot find any trace of her replying at all. 

When I asked her to make it very clear to him about breaking contact, she delayed by saying she didn't want to do it over the holiday season. After some bickering, I let it go. But the thought in my head is now, how can she be concerned over this guys feelings when I've been totally crushed inside.

Any advice or thoughts are welcome.
<bot>: Fiancee trading pics with old Uni friend, won't put her foot down despite saying she wants to be with me.