العلاقات

I am in a relationship for around three years now. We are having a very good relathinship. He has plenty of female friends and he goes out with them, he travells with them, he always send me photos of where they go what they do and I have no problem with it as I totally trust him... or used to. It all started last May. when a friend of a friend appears in his life. they had a very superficial relationship but chance made them one step closer as I understood. He told me about her and it was ok with me. Then.... I noticed he changed with me, he goes out with me, he respects me but i feel that he can not stand me, it is as if i am the one who is driving the whole relation and I am the one who is pushing him to do activities with me. I thought may be he is having problems at work or at his studies. I just thought I have to support him to pass this phase and I should not make a big ado out of the nothing. then a month later he became as before and ee returned to be as before. The issue that I discovered and i am still discovering is that he is hiding everything related to that girl from me. I found out that he travelled with her for ten days the period he was different with me and at that timehe claimed that he was with some one else.I am used that he travells with his female friends and i do not object to it but the strange thing is he is hiding it. she is in his life , Once he had a chat with her while i am sitting in front of him and he can not carry on the conversaiton with me because he can not stop chatting with her. I tried to act tactfully and took the phone from him , he became so nervous and she called a moment later, and he reacted as if he is astonished for her call as they ar so far and they are not even close friends and he refused to take the call in front of me, saying that he gives priority to spend more time with me, I was not convinced but i reacted quietly and let it go. He is travelling with her next week and he said he is travelling with a group of friends and he mentioned many names but not her name. I saw soem of her messages to him on Twitter that might have looked normal for me if he was not hiding her from me. Currently our relation has never been better and that is weired and it is preventing me from discussing anything with him. I do not know how close they are or what is exactly going on. I got all my information through twitter or instegram so i could not face him with any thing because i will totally look psycho if i did so. They do not even have a photo togeather, but it can not be a coincedence that both are going to Switzerland next week and that both went to Hurghanda for the same 10 days in June. Really i do not know what to do. I am torn apart and dont know weather i should talk to him but how to do that withought lookin as a psycho who is following him on twitter and instgram and so on..