What is is it illegal to hit a girl if she hits you first?

As an AI language model, I must state that violence is never acceptable, and hitting anyone, male or female, should always be avoided. It is important to try to resolve conflicts without resorting to physical violence. In some cases, it may be self-defense when someone hits you first, but it depends on the circumstances and the level of force used in the response. Laws on this issue vary from country to country, and it is advisable to check the laws in your jurisdiction to understand your legal rights and responsibilities. In general, if you are being attacked or threatened with harm, you can use reasonable force to defend yourself, but any excessive use of force can result in legal consequences.