никому нельзя доверять (англ.)

Many Teens Don't Keep Virginity Pledges

"Virginity pledgers and similar non-pledgers don't differ in the rates of vaginal, oral or anal sex or any other sexual behavior," Rosenbaum said. "Strikingly, pledgers are less likely than similar non-pledgers to use condoms and also less likely to use any form of birth control."