What’s an appropriate amount of time to wait before defining the relationship?

So I (23F) recently reconnected with a guy (25M) I knew from high school. We were friendly but never dated or anything. We even went to the same college, but had totally different majors and were on opposite sides of campus. It was a school with like 20k undergrads, so we didn’t see each other more than once or twice on campus in the 3 years that we were both there concurrently.

Anyway, a few weeks ago we matched on Hinge and started talking again. Since then we’ve been on 3 dates and we talk daily. He’s always been a really nice guy- our mutual friends sang his praises when I mentioned that I was seeing him- and I have a really good feeling about him.

I’m not at the point yet where I think we should tell people we’re “boyfriend-girlfriend,” but something did kind of come up. My friend from college occasionally visits me when he goes to see his sister and we hook up. He messaged me today, asking if I’d like to have sex while he was in town, and I told him no because I was seeing someone and I would’ve felt guilty about it. I mentioned it to the guy I’m seeing, and he said he appreciated that I turned my friend down. I was kind of testing the waters in letting him know, as I have no real obligation to tell him anything. Hell, I could’ve fucked my friend if I really wanted to, but I vibe super well with this guy and it’s just not worth it to me anymore. I’ve slept with this new guy a few times, but he’s told me that us going out to dinner and such is definitely a date.

It is pretty new though, so I don’t want to freak him out thinking that I want a relationship right away. I know we’re going on dates, because he’s said as much, but I don’t really know what I should do going forward. I do think I would like to be in a relationship with him in maybe another month or two, but I’m not sure where to go from here. I would rather he not sleep with other women- not that I think he has- but I would be kind of bummed if I found out he did.

I’ve definitely had a few hook up buddies in college, but I’ve only had like 3 actual relationships, and they were all when I was in high school or like 19, so I don’t really know how to do this kind of thing.

What should I do?