Wtf feelings?!?

Worm • Just trying to survive until the weekend
So this year I became friends with a guy through sports/mutual friends, and he's become my best friend. (that's a guy) We do a lot of stuff one on one like hang out at the mall/go to movies ect. But they've never been romantic or anything because we're friends. We always get razzed for being together because everyone assumes we're dating, but we don't care because we enjoy hanging out together. We do kind of flirt though, we sometimes hold hands and I'll play with his hair, harmless banter, ect. But it's never really meant anything. But recently I've felt different around him. Last time we hung out with friends and we went swimming it was really fun. He kind of laid his hand on mine and we held hands, our friends saw this and then thought it would be funny to have like a "fake wedding"  in my friends hot tub because we're literally 5. 😂 At the end of the "mock wedding" my friend said "you may now kiss the bride" and my heart just dropped and I really wanted him to kiss me. We didn't, but he picked me up and threw me into the pool 😂. But lately whenever I think about him or text him I get all fluttery. It's weird because he's my best friend and I don't wanna admit I have a thing for him because it would ruin what we have. Another thing is he's had a crush on a girl for 3 years! He doesn't want to date in high school because he wants to focus on studying, which I get. I'm just confused and a little weirded out because he's my little geeky guy friend and suddenly I have these weird feelings about him. He just makes me feel beautiful when I'm not wearing any makeup and I'm
In sweatpants, like he literally told me I was gourgous without makeup. No guy has ever made me feel like that. Man, 10th grade is going to be weird. Any suggestions? Has this happened to anyone? Advice? 
Sorry this post is so long!!! ❤️