I need advice PLEASE READ

okay so at my highschool football game last Friday, a few girls were drinking alcohol out of Sonic cups DURING THE GAME in the student section. I was standing with my best friend and we could smell it and (the girls drinking told me they were)  she told her parents who are cops and they told the administration of the school. at half-time, my friend and I went to Sonic to grab some food and came back and the admin took our cups and said whose are these and we said ours and he asked whose the next cup was and I said and then he asked whose the next one was and I said "last I knew *insert name of girl 2 drinking* had her stuff here" 

girl 1 ended up with an MIC and girl 2 ended up with a week long suspension from school. 

now I'm getting called a snitch and everyone hates me and my best friend is taking NO HEAT WHATSOEVER. my mom says I should throw my friend under the bus. 

side note* my brother is in my grade and my mom told my brother that it wasn't me it was my friend and hopefully he will spread the word.* 

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what would you do? throw your friend under the bus? suck it up? ps I'm I senior. help :( im losing all my friends!