>>6531965They know exactly what they're doing, it's legit pure sadism. They derive satisfaction from the frustration and longing that being around her brings while they fuck around with other dudes. Make an effort to see her as something you're not attracted to, treat her like just "another one of the guys", be frank about your sexuality (particularly talking about other girls, even ones you aren't really attracted to), while at the same time not acknowledging her sexuality in any way. Watch how quickly she becomes annoyed and upset.