I have a girlfriend , but is just an "screensaver" because I don't feel anything for her. Do you think that I have to tell her the true or break up our relationship? Also I'm dating with her brother ... really I need help

 

If you don't feel anything for your girlfriend, you should definitely let her go. If you are dating her brother, she will find out sooner or later and then it is going to be worse.  Having a girlfriend and/or boyfriend is not a laughing matter. There is another person involved who has feelings and deserves to be respected. Don't do to others what you don't want them to do to you.