My boyfriend and I have been together for four years. I am 28 and he is 32. He many good friends, both male and female. I get on very well with all his friends, except one. This one female friend has me worried. When he is around her, everything is about this woman. He will follow her around and won't leave her side. We went to an outdoor concert under a tent and everyone was smoking. I have asthma and asked my boyfriend if we could step outside the tent. his response was for me to stand by myself, he was staying with his female friend and her boyfriend. On another occasion, which happened to be my birthday, I was ready to go home after a long night, but his female friend and her boyfriend wanted to stay. So he told me to go back to his parent's house by myself, which involved a train ride at midnight to a very isolated station. He didn't even walk me to the station. He gets very defensive of this friend and assumes I am jealous. I am comfortable with all his other female friends, because he he treats me very nicely when we are around them. It is only this one friend where he acts in a different way. Is this normal? Should I be worried or accept it?