The answer to this question is more complicated than what is perceived in movies or television shows. But the answer is, once charges are filed, it is not up to you anymore.
Once a significant other is arrested for charges pertaining to domestic violence, they will be charged for those offenses. An officer is not going to arrest someone if they are not going to proceed with charges. To arrest someone, the officer must have probable cause that a crime is occurring or did occur. This is REGARDLESS of whether or not you or someone close to you says “I do not want to press charges” or “I do not want him/her arrested, it was just a silly fight between us.”
Police officers have a policy to follow and do not have to listen to anyone at the scene pertaining to charging or investigating a crime. They make their determinations based on a totality of circumstances approach which includes statements from parties involved, any visible signs of injury, and their years of experience dealing with domestic violence situations. At this point in time when your significant other is placed in the back of the squad car, the charges will be filed and they will be going to jail. If your significant other was arrested on a Friday or the weekend, they will be in there for the remainder of the weekend based on North Carolina law.
After the charges are filed and the case is set for court, it is up to the District Attorney that is assigned to his or her case to prosecute the case within his or her discretion. Most certainly, you are allowed to call, email, write a letter, or even appear at the District Attorney Office to try and get the charges against your significant other dropped. However, it will be extremely unlikely for the District Attorney to dismiss domestic violence charges off docket.