You can't sue a person simply because they had a relationship with your daughter. Your consent is unnecessary, however, as it would be illegal to engage in sexual activities with a 15 year old. The criminal prosecution of this man is likely the most realistic, and effective, legal recourse in dealing with the situation. Some of the acts you've described could theoretically fall under other torts but is it worth it to pursue a civil suit? Truly, this man is facing prison and being labelled a sex offender, so a lawsuit wouldn't be able to do any better. How would you or a court even be able to calculate damages. Besides, just because you sue someone and win doesn't mean they have the ability.
The only suit you could really pursue would be to obtain a civil injunction, which would likely be granted. Your child is a victim of a sex offense and that is a basis for there to be a no contact order between your daughter and this man. If you are being threatened or harassed then that is also a basis for a civil injunction as well.
What is the status of the criminal case? If this man was arrested then the court would likely have issued a no contact order already, although it would only be in the criminal case and not a separate injunction.
This is not to be considered legal advice nor does an attorney-client relationship exist.
This is a multi-faceted question that mostly involves criminal law. If other individuals are taking your daughter to places, you may have a cause of action for interference with your parental rights. You may also have an independent action for an injunction for protection against repeat violence.
I would encourage you to seek the advice of an attorney.
Tami L. Augen Rhodes
I agree with Mr. Trabin. You might have a couple of tort claims, but filing suit in civil court is exhausting, both financially and mentally. After what you and your partner have endured, do you want the added stress? If the criminal case moves forward this young man is facing serious charges and being labeled a sex offender.
Legal disclaimer: Ms. Braaten's answer to your question does not establish an attorney client relationship, but rather is meant to share knowledge with the general public. For specific advise on your case, you need to consult one on one with an family law attorney.