I have been dating my partner since the beginning of June. We both agree that things went very fast. He is 2 years younger (30). He has a LOT of friends. His social life is exhausting for me. I had made it clear that I felt very uncomfortable with guys' night out and that I would prefer not to be excluded. As far as I am concerned, my partner is welcome anywhere I go with whomever. He recently made plans to visit a female friend at her place. I was VERY upset when she called him to confirm the plan I did not know about. I have never met her. I did not know they had made plans to meet up at her place just the 2 of them. They have known each other for many years I believe. 
I still feel very strongly about this although I know that there is nothing between them (I cannot talk for her). He is only trying to be a supportive friend as she is anorexic. 
Despite all explanations, I feel very upset and strongly about it. 
 
I do not know how to find a solution and I feel guilty to deprive him from his previous lifestyle of bachelor. 
Has anyone been in a similar situation ? 
How can I put it to him in a way that is not going to make him feel strangled since the relationshhip is so young yet so close ? 
Thank you for sharing your experience.