ADVICE NEEDED PLEASE

I need help. So there is this guy and I haven’t liked someone in so long I forgot what it feels like. I don’t know if I like him or if I’m just a horny teenager 😂 but every Time I think of him I just smile and get this weird feeling in my stomach. But we are great friends we went to school together, we work together he drops me off at home when we work together and I never had these feelings until we went to a party and we didn’t even talk a lot that night he would get me drinks but we hanged out in our separate groups. When I left I had a big hug and that’s when I started getting all these feelings. And the worst thing is I would go for it but my twin brother is really good mate with him and I’m embarrassed cause Im self caution with my weight and I hate my stomach. And I just get embarrassed. But the thing is so I like him or is it just Lust ❤️