Normally I'm 100% against of going back with your ex, because they are your ex for a reason. However; in my case the only reason I broke up with him was because he was too busy with school to pay attention to me.
It was 6 years that I first messaged him and I had no idea how much of a wonderful Master he was that that time. I had to go through hell a few times to realize that he was caring, actually paid attention, knew my mood and how I felt without me saying a word, and if I'm not comfortable with anything he will drop it and never bring it up unless I did.
I'm very glad that I just happened to be bored and wondered how he was doing. Also thank you awesome memory or else I wouldn't have been able to even message him.
My point is if you ever want to get back with an ex list what was good and bad about the relationship. If the bad things aren't too horrible then it might actually be a good thing to get back with your ex.
Side note: Sadists are hard as hell to find and I'm soooo glad that he is a sadist. I have tried being without pain and it just isn't my thing. I need pain to be able to feel anything.
