It is too complicated a social situation for a child to navigate.She'll see boys at school, clubs, and church (if you're church-goers).I'm a high school/middle school teacher and this is way wrong. more than likely the girls his age don't want to date him. You are not allowed to go out with this guy, or any guy.Simply put, a 16 year old boy is looking to have sex with her. If you disobey me, you will be punished." but be careful of the backlash from her.
It is critical that you set the boundaries for her, that you parent her.Lastly, remember, you are the parent and it's your house, your rules.