Dream Interpretation: I don't understand

Visitors Dream: "I keep having dreams about my ex and his new girlfriend. Last night I had this weird dream...

I was in my old neighborhood (the one his family still lives in also.) I walked around the corner and I saw his house. I went to the door to say hi to his mom and little sister. They let me in. I didn't know that my ex and his girlfriend happened to be home for the weekend also. I sat on the couch talking and stuff. My ex came downstairs and conversated with me. I was getting ready to leave his house. We went outside and we saw the ice cream man down the street so we walked down the street with his little sister and some more people.

When I got ice cream I noticed I had left something. He was already gone back to his house. So I walked back, and when I got there his girlfriend, him and his mom were in the driveway. I got mad that second. Walked up the drive, went in the house, got my stuff. I stood in the driveway to write something on a paper on a table. His girlfriend was to the left of me in a chair, and she said something to me. I stopped and looked at him and he was like maybe you should speak....and I looked at her and I said, 'Look, I don't like you. I don't know how many times you've TRIED to talk to me but I don't wanna speak to you.' And she said something under her breath and I slapped her.

Then I woke up in a rage thinking why do I keep having dreams about them? I do know that I'm a little jealous and still upset but I can't figure these dreams out!!!! SOMEONE HELP ME, PLEASE!!"