This makes a lot of sense. One would expect girls who are dependent on, and afraid of losing, their romantic partners to be less willing to risk angering them by advocating for their own sexual health than those who are content in their own skins. It's also a great reminder of the importance of teaching self esteem and relationship skills as part of your sex education curricula, not just sexual mechanics. After all, it doesn't do young women any good to know how to put on a condom when they're unwilling to bring up the subject in the first place. It's also hard to take care of yourself when you're less concerned with your own well-being than that of your relationship or your partner. You just don't have the motivation.