Am I delusional for getting my hopes up with a guy who used to date my ex-friend? (17F & 17M)

I (17f) have had a crush on this guy since 2022. We were friends back in school and had a class together — it was my favourite because we sat next to each other and talked a lot. I haven’t seen him in person in over a year since I left school, but I’ve never fully gotten over him.

He used to date my friend. They were on and off and had a messy relationship. He cheated on her twice, which I know is a huge red flag, and he told me recently that he was talking to other people because she wasn’t showing interest in him anymore. At one point, she made him block me, so we had no contact for months.

Then recently, he added me back and messaged me just saying “hello” — I got way too excited. He apologized and said he heard from a friend that he was horrible to me, but I genuinely didn’t think he ever was. We used to joke a lot and make fun of each other, and I said way worse things to him, but it was always playful. He said we were like “best bud secret.”

We started talking again properly, and it’s been really flirty. He called us “besties” and at one point, when I said he should stop talking to his ex because of how she treated him, he said, “Woah, calm down, you can have me,” which completely threw me off. I still don’t know if he was joking or serious.

He opened up to me late at night about really heavy stuff — he told me his ex physically abused him, and other heavy stuff about his mental health and life. He also said people think he’s horrible and he’s trying to change. I told him I never thought he was horrible. He told me I helped him realize how toxic things were with his ex, and he said he was going to tell our mutual friend the truth about the abuse, even though he was scared his ex would lose all her friends.

He told me he blocked his ex. He’s been replying to me quickly, saving my face snaps in chat, and even said he hasn’t snapped me back yet because he hadn’t washed his face — which I thought was kinda cute. The vibe is really good right now, and it feels like it might actually go somewhere.

But… I’m scared. Scared that he’s joking. Scared that it’s just a game or a prank or that he’ll just stop talking to me again. I’ve never had a proper relationship, only situationships with two girls. I’ve never had my first kiss. I’m super insecure generally and really scared of intimacy — especially with boys, because I’ve never experienced that side of things before.

I like him so much, and I know I probably shouldn’t — he’s my ex-friend’s boyfriend (they’re on a break now, apparently not getting back together), and he’s cheated before. But let’s be real his ex is a HORRIBLE girl, so honestly I wouldn’t feel bad for getting with him, she’s literally getting with her cousins bf right now. But he makes me laugh like no one else, he’s tall, sweet when he wants to be, and honestly he’s like my dream guy (aside from the red flags). I feel like I’d be such a good girlfriend to him and could treat him so much better than his exes did. I kind of want to “fix” him — I know how that sounds, but it’s how I feel.

Right now I’ve decided not to double text or chase him, just to let him keep the conversation going. But every time he takes a while to reply, I spiral a bit. I want to message him all the time, and I get way too attached too quickly. I’m just scared I’m setting myself up for heartbreak, or that he’s playing with me, or that it’ll all mean nothing to him.

Any advice?