Matt- Now dont take this the wrong way-- You are a bit of a drama lover as well. Simply tell her the truth, why lie?? Simply state, that you found it offensive that she was basically making fun of you for asking the teacher a question, and that as adults that is inexcusable in your eyes and that you would prefer not to help her in the future. Be a grown up, don't lie to the liar, as this just makes you a liar as well. You seem to be a sensitive sort, which in itself is not a problem, but you seem to let stupid little things bother you. Tell me what is so important in this situation?? That you were nice to her and she reciprocated by laughing at you?? Welcome to real life Matt, just because your nice to someone doesn't mean they will be nice back. Let it roll of your back, it is certainly not worth stressing yourself over. And congrats on getting such good marks.