The events are attended by fathers and their teenage daughters in order to promote virginity until marriage. Typically, daughters who attend a purity ball make a virginity pledge to remain sexually abstinent until marriage. Fathers who attend a purity ball make a promise to protect their young daughters' "purity of mind, body, and soul."

Now if I was more conspiracy minded I'd say this sounds like some fucked up swinger-party but it's probably just some fucked up religious purity cult nonsense.

edit: "Wilson advises fathers to praise their daughters' physical attractiveness: "I applaud your courage to look your daughter in the eye and tell her how beautiful she is." Participants are described as "dates", and, according to Glamour magazine, could be mistaken for heterosexual romantic partners in the absence of information about their parent-child relationship." oh god oh fuck