Which guy do i choose?

So on my birthday (November 17) i was asked out by a guy who i have know since around August and i said yes because i have like him since around October... The only problem is that my best friend is a guy and i have known him for a long time but have only liked him for about a year and a half. I didn't tell him because i didn't want to ruin our friendship by dating. In August of this year he liked me and i didn't know until around October. I found this out because he dated a girl named Aaron and she was mad at me because she thought he broke up with her for me, but that was not the reason. He then dated two other girls this year and used my sister. The funny thing is that me and my sister have the same taste in guys so we have pretty much dated or liked the same guys with an exception of like 2 or 3 guys. On December 19 my boyfriend didn't show up to school and i didn't have a sweatshirt so my best friend let me wear his and because it was his school basketball sweatshirt it said his last name on the back. My boyfriends friends switched up the story saying that i wore his sweatshirt because i like him and my boyfriend wouldn't find out, but nobody knows that i like my best friend. The next day my boyfriend came back to school and his friends told him he didn't look or talk to me until the end of the day when my best friend went to talk to him with me. He understood after a while because we said that the jacket meant nothing other than i was cold, but that night me and my best friend had a band performance and i needed advice with something, so i told him and i said "I like a guy but im dating someone and i dont know what to do. I have liked him for a while but i don't think i would break up with my boyfriend for him because i dont think he likes me." He tried to guess who the guy was because i didn't tell him. The next day was the last day of school before Christmas break and he didnt show up. My sister was looking for him to talk to him and i told her he wasn't in first or second period so she told me he likes me in third period and she also told me she likes him and i told her that i like him but this time nobody knew besides us. I ignored my boyfriend because i dont know what to do and he asked my sister if i was ignoring him and she said she just has a lot on her mind. She also told my best friend that i like him. Someone help me i only have till January 6th to figure this out. Do i stay with my boyfriend or date my best friend? I dont want to say im breaking up with him for my best friend because then that means that the jacket was more than me being cold and i wish i could say it was nothing more than me being cold. My boy friend also made me cry and my best friend and my sister and me all know that my best friend can treat me so much better but i like both guys!