Dream of girlfriend, sexual, sofa, dancing

Last night I dreamt that my brother and I were sitting on the sofa -- I on my laptop and him watching TV -- when his wife came into the to start pressing his clothes. Music starts playing from my laptop and my sister-in-law starts dancing and as the music progresses, her dancing becomes more sexual. I then realize that she's basically dancing for me. I look at my brother and he seems agitated and annoyed. I then pull her closer and I tell her "I don't know what is going on with you and my brother but you should know that acting this way won't help." She then goes on to tell me "Well after the pictures, I just thought you might want some revenge." I immediately jump off the sofa and I ask her "What pictures? Did he do something with [my girlfriend 's name]?" she says " Well they're deleted now, but yeah, he fu.cked her like a w.hore." As she says that, I swing around punch my brother in the face and then start choking him.