I have a current issue with a friendship that has got me so down. I am not sure if a big reason I have such an issue is because of social anxiety or if it is normal. I have had an on/off relationship/friendahip with a guy for over 10 years. Its a long story. But 5 years ago, when we were not in good terms again he connected with my sister who was under 18 at the time. That got me so infurriated that the drama it caused made him block both of us on Facebook. About a year ago he unblocked her and they started talking. I, having changed much over the years, tried to reach out to him via a friend's account with no luck. I had heard of her being in communication with him so I recruited her help and we started talking again. I had wanted to get in touch because I was finally at a point in my life where I really wanted to give having a relationship with him a real shot. Well sure enough we hit it off right away and that appeared to be very possible. But there was a new blocker. Him and my sister were becoming good friends hanging out and I would hear of it, which would just weird me out. I had said something and his immediate response was he can talk to and hang out with whomever he wants. Clearly this was going to be as much of an issue as 5 years ago so I left it alone. But as the weeks went on I just couldnt shake off the weirdness so I ultimately told him it isnt working out and that I think I just really wanted to make amends is all. So it was left at that. A couple of months later I thought more on it and it really upset me that I really couldn't persue a relationship with him due to his platonic involvement with my sister. So I texted him out of the blue and we had a nice chat and then he asked why the message out of the blue. So I told him. I said because I was thinking of him and wanted to tell him thw honest truth of why I ended it. "I just cant be with someone who is my friend's sister." I thought it was a simple enough of an approach. His response? Basically, "You should see a therapist for that." Well long story short, I blew up and it wasn't pleasant for a couple of days as i ragged on him and desperately pleaded my case why the whole thing was ridiculous. The torment ended with me making amends by having all 3 of us meet up as if it would be easier if they didnt feel so secretive. Since then, for about a month I have been acting pleasant, messaging him frequently, pretending nothing is wrong. But I die a little on the inside when I know of them 2 hanging out and I just want to end it again. On one hand I know I should simply end the friendship, I dont need that stress. On the other hand, I feel it unfair I should have to. Its a fighting struggle. Ultimately I plan to tell him again why it is ending. But I know it wont do anything. I know Ill still have to live knowing they're still friends. It just wont hurt as much if I dont have to hear about it by also trying to be freinds. Ultimately I dont know who is in tye wrong here. Both him and my sister have told me to get therapy. I feel like I have no support, so betrayed, and neither of them care. I have done research to see if this is a normal circumstance, as far as I can tell, it isn't. But I feel hopeless getting over it and I dont feel like I need a therapist just to get over something that shouldnt be. I know part of this roots back to in general not wanting to share friends. I work better when my friends arent shared with other of my friends. They can have their own friends, thats fine. But why would I want a friend who is my sisters as well? How am I to ever talk to either of them about problems with either of them? Just doesnt seem natural.