Replying to Arguments for getting caught with alcohol

Alright, so im a sr, im 18 years old and i drink often. My parents know i've drank before and i told them a shitload of stories from sr week last year that i went to and how i got plastered and all this. I still hide my alcohol anyway, just because. So they found 2 handles and 4 water bottles full in a backpack in my car the other day and now apparently i'm in troube? they haven't talked to me about it yet, any good arguments that i can get out of getting in trouble?

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