I had met this guy (let's call him Cody) on Grindr. I wasn't looking for anything serious, since I've only been single for a year since I broke up with my ex, but he managed to change my perspective and I absolutely wanted to date him. We had a lot in common, he seemed very kind and caring, and even tried my favorite video game without me asking him to, which I know sounds silly but was a very big deal to me. He was hitting every mark, until our first argument. This is two weeks in, and I was contemplating just deleting the dating apps entirely, when we had the first argument. I'm not sure if leaving was an overreaction or not. He talked about his ex a lot, but I let it pass because they were together for 12 years and I didn't really feel jealous about that, but what did bother me were the subtle comparisons he'd make. "My ex had long hair like you," or "my ex smoked too and I'd join him." I wanted to set up a conversation about it, and I decided that waiting would only do both of us a disservice. He called me paranoid and said I was essentially implying he wasn't over his ex (I hadn't, this is the first time I even pointed out the observation). I was able to let that go, but when he said "sorry for hurting each other's feelings," I immediately felt my skin crawl with the memory of my narcissistic parents and how they would distribute blame when they would hurt me in some way. Was ending things here an overreaction when otherwise he felt like a match? This quickly devolved into a very long conversation, and I honestly regret not leaving it at the messages in the pictures, but this is also the first person I've dated that I actually miss after it not having worked out, at least in the last few years.

Edit for clarification:
I'm not bothered by him actually mentioning his ex. I understand that a 12 year relationship is almost half of his life, and I accepted early on that hearing about his past inherently meant hearing about his ex. Where I took issue was with him comparing me to his ex on multiple occasions.

In that regard, I was not terribly bothered by it, as I understood the inclination to compare something new to something familiar. However, I felt as though after two weeks, I had to touch on the topic of him comparing us. I wanted for things to become more serious but it was a genuine point of concern going forward.

Nothing about his ex was a deal breaker for me in the slightest, as I understood where he was coming from.

As this was my first attempt to actually have a conversation about the topic, I found calling it paranoia to be a bit extreme, especially since I only pointed out an observation.

Even the paranoia line was something that wasn't a breaking point for me, just a major sore spot.

The real thing that did it for me was the non-apology afterwards.

Edit Volume II: The Runes
Since people keep asking,
I had 3 pet rats named after Elder Futhark runes. He had a box of runes he made with his ex that he gave to me as a gift after he heard about the rats and that I like wizard-adjacent stuff (though the Kenaz rune was missing, so I made my own to complete the set). I wouldn't use secondhand runes with pre-existing meanings for runecasting, especially since I have my own set. I just accepted the gift because I appreciateed the thought behind it. Ultimately, he told me to just keep them, but I'm not sure what to do with them.

AIO I (26M) broke it off with a guy (34M) after two weeks after our first argument