It sounds like this situation is causing you some concern. While I can't interpret the real-life scenario directly, if you dreamt about this situation, it could represent feelings of insecurity, jealousy, or anxiety regarding your relationship. Dreams often reflect our subconscious thoughts and feelings about our relationships and the dynamics at play.

If you dreamt of your girlfriend's ex reaching out, it might suggest you are processing your feelings about her past and how it might affect your current situation. It could also indicate a fear of losing her or concerns about her loyalty.

Consider the emotions you felt during the dream. Were you anxious, angry, or indifferent? These feelings can provide clues about how you might want to address the situation in your waking life. Open communication with your girlfriend about your feelings might help alleviate any worries you have.