For backstory: when we first met, in the first week, I explained that I had a red line of staying in touch with people you've had a past relationship / slept with. This is due to being hurt in the past and just a general rule I have.
DP agreed.
However, on many times throughout our relationship (5 years) he says I'm the reason he's lost friends. From my memory, 2 of his good friends he has slept with. He agreed to cut these people out to continue dating me one week in to knowing each other. I use "friends" loosely.
One he had known growing up and hadn't spoken to her at all in a few years before we met and she hasn't attempted to speak to him at all in our relationship. He hasn't been back to his hometown either as all family moved from there years ago.
The other friend was a fellow professional in a house share, they slept together when drunk and she moved out just before we met. I agreed to meet her when we first started dating however on the night, they had an argument and she never tried speaking to him again.
His loss of friendships to me seem unrelated to me. We moved from our University town where he stayed for 10 years and to London. His good friends are still there.
The friends he lost are ones who I've had no impact with. They simply just must not really want the friendship. He has made attempts to meet them that they've cancelled. Some just have moved on, most have families and are settled all over the country.
I also will say, he's made new friends at work etc and I've introduced him to my friends and had parties etc. He has become close with one friend's boyfriend but the rest don't really like him - I think he isn't particularly fun socially, he comes across a bit self obsessed. He can also only make friends with new people if they're interested in football or horse racing.
I just don't know how to stop having this argument. It also makes me incredibly anxious. Every time he will automatically bring up those girls as friends I made him lose but he can't back up why he's lost the others, especially men.