OMG, this is the worst day!! i need boy advice from a boy!!!! PLASE.?

Ok soo... I have a house in pennsylvania and i go snowboarding every winter at a ski lodge. So this winter this boy has really caught my eye. and finally i talked to him ,and from there he seemed to really like me, he told me that he was waiting for me to talk to him all day & than later on that day we hooked up. He asked me if i was going to there the next day and i said i'm not sure, probably. and he said that he hoped i did go. So it turned out that i couldn't go the next day because i had mid-terms and i had to study. I couldnt go back up for another 2 weeks. So than finally today i seen him for the first time since than. As soon as he seen me he said "Oh hey i know you" and i said yaaa i know you too. He than asked to go snowboarding again and we did. He asked to sit on the lift with me twice. The first time we were on the lift he asked why i didn't go that day i told him i might of been going, i told him because i had to study for midterms. Than we were just talking. Than the next time we were on the lift we hookedup again. We went inside after that because it was cold. On our way going to go inside he was talking to his friend. and While he was talking to his friend i guess he didnt realize they were walking ped me and i overheard him telling his friend "See i told you, she just had to take exams at school" So obviously he wasn't talking bad about me. But than all of a sudden he just stopped talking to me. our tables were really close, but my back was faced towards him so theyre was no eyecontact. than later on i saw him talking to another 2 girls. My friend said that they weren't pretty but it seemed like they already knew eachother. It was just wierd, becuase we stopped talking at like 4- and than he left at 7. What does this meann, why would he just stop talking to me.