I don’t know what the consent of her parents has to do with it. The state prosecutes and convicts on behalf of the people in society.
As to what they might charge, it’s already been established in this thread that she’s underage in his state. Depending on the laws in his state, all he would have to do would be to (if the laws are similar in his state):
If he did any of these things, if these laws apply in his state, he is no longer innocent as to the laws of his state.