Meaning behind dreaming about an Ex?

Quick details, I dated a guy for 3 years, ended badly but we both mutually agreed the relationship was over. Dated a bunch of people since then, and now have been married for 6 years. I had a dream last night that started out with me and my ex at a car race as friends, then we started to get cuddly and it was comfortable, even though the last time I saw him it was very uncomfortable. What could this mean?