I'm clueless with a capital C

So, there's this guy and I don't know I like him or I just wanted him physically due to his attractiveness. So I was friends with benefits with this guy and only kissed him at first but then I had intercourse with him (it was very awkward due to it being my first time). Before that, he had a girlfriend then they broke up and then after we did THAT he got another girlfriend. And so I decided to cut all ties with him because I felt really attracted to him and couldn't stop thinking about him (also I want to point out he was a senior last year and then graduated). So, I thought I wouldn't see him anymore this year. And while being on summer break I was doing good. I stopped thinking about him. But then it happened! So I start the new year and try to find where my class is and guess who I see. A friend? My sibling? Uh my Mom? Nope! I see him walking down the stairs waving saying hello. When I tell you my heart dropped and did a three-sixty….it did! So I casually greet him back and I ask what he's doing here, he says he had to help his friend with something (I don't know if that's the actual truth looking back at it but whatever). So he then I being to depart to find my class then he says “wow so I don't get a hug?”, And I without thinking said “you can get a hug come here” (I'm literally banging my head on the door WHYYYYYYYYYY STOPPPP IT WHAT ARE YOU DOING?!). So I give him a hug and we finally leave each other. Then once I got to my house I told my friend about it and he was like this “you like him! Just admit it! Try and be with him……and he's lying why would he be at school if you said he already graduated? He probably failed…that hug meant more. No dude hugs a girl all touchy touchy when he has a girlfriend”. So I go to school the next day. BAM! I see him again at school. Like, I believe he passed- I mean I saw photos of him in his cap and gown with his parents. Like you can't fake that. What do you think is actually going on? Is he just playing with my emotions or he's just being casual like he always is and I'm overreacting?