total backfire

Erin woke up, got dressed and as she mounted the bus to school she saw Susan sitting beside her lackies.

Erin barely concealed her grin as she sat down, but as the bus started she suddenly felt her own arousal appear. As the ride slowly continued her need to masturbate became more obvious to herself and she realised that instead of her initial assumption that she was getting off on Susan's humiliation, there was some trick.

Her mind raced as she sat at the back of the bus, alone and clutching her crotch.