that going to make you seem really guilty though also. my suggestion would be to play it chill, just be like "cheting? who me? come on ms____ you know i wouldnt do that. sorry they look alike though. is there anything you want me to change or re do?" basically suck a little it, but not too an annoying point and get you shit on lock with your friend BEFORE they talk to you, just in case,
also if you get called down to the office your fucked.