Me and my best friend are in a fight.?

Okay so me and my best friend are in a fight. She wasnt at school today so she asked me to get her stuff out of her locker for her. She and I are super close so she didnt care if i looked at the stuff in her tr (Ive done it before) These 2 friends we have called her and were saying i took stuff out of it ( i didnt) and then this guy i think she likes (even though she says she doesnt) told her that i gave her stuff to him from her locker (he wasnt there when we were at her locker) and he wasnt gong to give it back and i never took anything out of her locker and gave it to people to keep. The only thing i took out was her tr. She got mad at me when he told her that and she was telling me to stop lying and me and another friend told her no one had her stuff except her and she wouldnt believe us. Shes believing her "best friends" over a guy. What should i do about it?