My Best Friend (?)

Me and this girl go a long way back, and we've known each other for about 4 years now. I'll try to give you guys a bit of context so it's easier for everyone aight :D

As I've said, we've known each other for about 4 years now. Let's call her Sam. We got pretty close and there was talk going around about the two of us, but it all died down and I kind of drifted from her when I got together with this other girl. It was quite a toxic relationship looking back at it, but we kind of held on and we broke up about 6 months ago. The breakup was really hard for me, as any break up goes, but Sam was always there for me even though we've drifted off quite a bit. I slowly recovered and got close to Sam again, and on an innocent bus ride to dinner with a bunch of friends (her included), we were talking about Ramen and I said "We should go there sometime" (I meant for "we" to be the group of friends) and she said "Are you asking me out?". I laughed and said "You could take it that way" and afterwards I texted her "Someone's making moves once I'm single". I did add in the "I'm joking" because I didn't really want to seem too forward, but she just laughed and said she knows. We did end up going out to eat ramen, but it wasn't anything special. Just a great day out with a friend.

Fast forward to a week ago. We've grown a lot closer and all, gone out a few times but its been nothing special. There's been touches, flirting and random eye contact where she would hold sometimes and we would smile, but I've always discounted all this on the account of us being really close friends. She asked me out for a school concert to support another of her guy friend which also is one of my good friends, so I agreed and it was all set.

Yesterday was the day of the concert. Our classes all ended early at 1245pm and the concert only began at 7, so the both of us had a lot of free time together. She seemed a lot more flirty and touchy, so I kind of reciprocated that, feeling I've gotten the "green light" to be flirty in a way HAHA. We went out for lunch together, and it was the best "date" we've had ever. We laughed like crazy, talked about our lives and dreams, talked about masturbation (LOL) and we had so so much fun. We walked so close together and there were moments I felt I could just hold her hand and she wouldn't have minded. She did drop some questionable hints (I was wearing a T-shirt representing her house in our school, while she was wearing a shirt representing my house, and she said it was a statement) (Her friend texted her where she's been been before the concert and I jokingly said "to have sex with me" where she replied "in your dreams" and punched me in the arm), and all in all, it really felt so different from all the other times we've went out.

Here's the weird part. On the way to lunch we talked about relationships and all, where she said she wants to go overseas to university after college which kind of hit me hard. She also said she doesn't see a relationship with anyone working out now, for she would be going away anyways and didn't want to do long distance. From my side, in all honesty (and I told her), I felt relationships at our age were just for fun for they most probably wouldn't last till marriage.

Back to the concert. It was pretty meh, and afterwards she went home on her own (I offered to follow her but she declined) and I hung around with my friends I met at the concert awhile after. She texted me after to say she had a lot of fun, and we both agreed to go out more often.

I've always kind of had a bit of feelings for her which I've tried to keep down because as I've said, I don't feel a relationship now would last and I didn't want to ruin our perfect friendship. But after yesterday those feelings really broke through, and I'm now really confused with what I should do. Keep those feelings to myself and wait for a better time, or tell her that I love her?

Thanks for bearing with such a long post, hope to receive some great advice from you guys :)