That's not a big deal. Tons of high school kids get drink alcohol and get drunk. I did, with my mother! I got drunk at New Years last year. And I got drunk in China (from one dixie cup). I really don't drink that much on account that I get drunk too easily. My point is that being accused of such isn't really going to hurt anyone's reputation because it's pretty much a common occurance.
Also I was accused of looking at some girls ass. I didn't and I denied it. My co-worker didn't beleive me, but oh well. We had some laughs with it. That kind of accusation is not that big of a deal. Besides, the girl didn't even have an ass, I checked that out waaay before that incident

. Being accused of hitting on some girl ain't that big of a deal either, it could have been worse.
Like someone could have accused you putting the moves on some guy or something.