There was virtually no privacy in our relationship

[Namchanged]

I have name changed because I want to show this to my ex.
When we were together he told his friends virtually everything including our sex life. How long we were at it for.. and mentioning that I felt sick.. I felt I had no privacy generally. He crossed my personal boundaries by doing that. Based on his behaviour it could be assumed that anything we said or did would probably be parroted back to them. They had input in our relationship. he would also be influenced by the things they would say and start talking like them with the way they would word things or with their ideas and opinions. It was if they were involved in our relationship, I didn’t feel as if I was with just one person and that made me really uncomfortable.
It was one of the reasons we broke up, and he’s been saying my feelings are wrong and standards unrealistic and unreasonable and others talk to their friends about their relationship and partners as well.
I've tried to explain to him why it was wrong it made me feel uncomfortable but he doesn’t understand. Can someone help explain it to him?

Oh you have to laugh at his lack of self-awareness!

For a start, you haven't done what he's done. Because this is an anonymous forum, so no privacy issues. And also, you haven't told us about sensitive stuff like your sex life. So no harm at all done to him.

He however - acts like a 14 year old. No, grown adults don't tell their friends intimate relationship info. Why would they? Noone who respects their partner talks to their friends about intimate stuff they don't need to know. And what sort of friends want to hear that stuff? The fact you said he relied on his friends' opinions, and changed to talk like them, makes him sound very naive and immature. Certainly not grown up enough to have a respectful, adult relationship.

My final comment - you've left him. For very good reasons. You don't have to convince him you were right to do so. His opinion in this is not relevant. You left, you were right to do so. He doesn't need to agree. And he isn't likely to agree is he? He doesn't want to consider he might be in the wrong. It should be enough for you to know you did the right thing, and you're well rid.