Dreams about living in a big, abandoned house often symbolize your inner self or your mind. The house being dusty and filled with giant spiders may represent feelings of neglect or unresolved issues in your life. Spiders can symbolize fears or anxieties, and in this context, they may represent things that are bothering you or emotions you need to confront.

The act of trying to clean out the rooms suggests a desire to make your life more comfortable and orderly, indicating that you are actively working on personal growth or resolving past issues. Chasing the spiders away signifies your efforts to confront and eliminate these fears or negative emotions.

Seeing both your current girlfriend and your ex-girlfriend outside may reflect feelings of conflict or comparison between your past and present relationships. This could suggest that you are processing your feelings about love, commitment, and perhaps unresolved feelings for your ex.

Overall, this dream could be encouraging you to address unresolved feelings and fears in your life, especially concerning your relationships. It may be helpful to reflect on what aspects of your past you are trying to clean up and how they might affect your current situation. Consider having an open conversation with your current girlfriend about any feelings of unease you may have.