So I [28M] have gone out on a few dates with this girl [24F]. We started out as friends and were hanging out platonically in the beginning. After a few weeks, she gave signals to me that she was attracted to me, and I was attracted to her. So I steered one of our hang outs into a more romantic setting where we went stargazing and admitted we found each other cute/liked each other. The day after, I invited her to a party and we went back to my place and watched a movie, where I escalated and we made out for hours. She gave me an innocent vibe so I didn’t want to hook up immediately so the “date” ended after making out. She thanked me and was very into me at that time.

After that, she hung out with a friend of mine (who is M but gay) and that friend asked her about her dating life etc. which he then told me and my friends about. I was a bit uncomfortable of him probing her on my behalf but didn’t say anything. I invited her out on another date which she agreed. This is where I fucked up a little bit, where I took her out to a really nice restaurant and the date became super formal and the chill rapport we had beforehand turned more into interview vibe. We still went back to my place and made out (almost up to sex). I asked her if she wanted to go further but she said not tonight.

At the end of the date, my friend asking about her dating life etc. came up and I mentioned he told me about it, to which she got surprised. Then I felt kinda bad and apologized that I didn’t ask him to probe her and report to me or anything. She laughed it off but I felt that she was a bit uncomfortable.

After this date (which is like 3rd date ig), she has gone cold and told me recently that she thinks she doesn’t want anything romantic but wants to stay friends, which I agreed (I like her but I’m experienced enough to not care about getting “friendzoned”). I understand how I fucked this up but wanted to get people’s feedback. What should I do to not have something happen like this in the future?

TL;DR: Started platonically with a girl then turned romantic but I fucked up the third date and she’s gone cold and wanted to just be friends. What exactly did I do wrong and how can I improve?