Not sure if this guy [26M] likes me [24F] but he has been going out of his way to spend time with me. How do I escalate things without looking too into him (in case he doesn't like me romantically)?

So I'm currently in graduate school. I met this guy through mutual friends (also in our class). Over the past few weeks, he's been going out of his way to spend time with me.

First, he would invite me out to group gatherings and then started asking me to do things one on one with him. He even waited outside my exam hall for 45 minutes while I finished an exam, just so we could spend time afterwards.

He wanted to go to a recent party together. We walked in together and everyone kind of stared at us, which was a little weird for me. He's made it clear that he's single and so have I.

Now normally, I would think he was into me, but he's such a nice, friendly guy that I'm thinking he's just being a good friend. I've also misinterpreted signals before, which doesn't help (although it definitely wasn't to the level this is at).

We're currently on break right now and we don't have a "text frequently" situation going on. How do I escalate things without directly asking him out?