<human>: I'll try to keep the explanation simple.

I am from country 'A' while my girlfriend is from country 'B'. We both met while volunteering in country 'C'. After we both finished our volunteering I came to country 'B' to see her for a few weeks and since come a 3 times for a total of 10 weeks. 

I found out soon after we started dating that she talked to a guy also from country 'A' whom she also met while volunteering in country 'C' and she later told me they had previously had sex a couple weeks before we started dating and was told that the only reason they never started dating was because the guy couldn't afford to visit her.

Now to the issue, I know she still messages him frequently and they Skype together at least once a week (On occasions, when she has told me she was studying, I later found out she was in fact Skyping him). I have told her before that I don't feel comfortable that they still keep in such good contact but she turns it on me by calling me jealous and that I don't trust her.

I was recently in country 'B' and couldn't help looking at her messages to him, I saw that her sent her clothes and they talk about how they miss each other and want to visit each other as well as how they should hide certain things so as not to make me jealous such as her liking his facebook posts or other things.

My question is, am I wrong for being upset about this or am I just an overly jealous boyfriend?

Summarize the given text in a few sentences.
<bot>: LDR GF still messages & Skype's guy she had feelings for and sex with. Am I wrong for not being comfortable with the situation?