Originally Posted by mttgb
I am not sure if a punishment is appropriate
My initial reaction to reading this was, what kind of lousy father are you. But then I thought about it more and I realized you are right. This is not a case of punishment. You don't want to give her the impression that she is a bad girl that deserved punishment.
But you do have to realize that this is not allowable behavior. You need to impress upon her, either alone or through the female confidant, that this is dangerous behavior with very serious consequences. She also needs to understand that she betrayed a trust and that also has consequences. Those consequences mean that she will have less freedoms until she earns back your trust.
And there is one more thing. You need to talk to the parents of the boy and make sure they are aware of their son being sexually active. Also the age of this boy matters. The older he is the more it may be that he is taking advantage of your daughter.