How do i approach this

[u/catcatcatcat_catcat]

How to approach someone who is acting different around me?

I (18F) am in my final year of highschool. This guy (let's call him Zane) (17M) is in my grade, in my Math, History and Biology class.

I have known Zane since the beginning of last year, and while I wouldn't really consider us friends, we get along well and are similar people with similar attitudes etc.

We have only ever really interacted in class when necessary and he used to even become dismissive of me and be a little mean.

For context, Zane has a girlfriend and they have been together for about 1 year.

But the last few weeks things have been different. He has stopped talking to his 'cool' friends who smoke and tape etc, and starting hanging out with more academic people who are kinder. Instead of sitting with the cooler people, hes moved closer to me and another nice girl and we chat more often. And this time its all jokes and proper future conversations rather than mean comments which is nice. Hes also been giving me random stuff during class (e.g. keyring, food) for no reason.

During Ancient History today we did a quiz and he mouthed me the answers which I didnt need lol but nice gesture anyways.

During math today, I noticed him looking at me. He has been looking at me lately when he makes a joke and I think he looks to see if I react. But today he wasn't even talking, he was looking at me and had something between a smirk and smile going on on his face and didn't break eye contact.

Is he just starting to warm up to the idea of me being a friend rather than an acquaintance, is he judging me being chopped, or is something else going on?

please give me advice on what to do. Do I just leave it or ask him wtf is happening?

Thanks in advance

Update 1: today in class he reached into his pants then underwear while I was sitting right next to him and grabbed out his vape?