Why would my ex reach out to me after years of no contact?

Why would my ex reach out to me after years of no contact. He has a wife and 2 kids. I had no idea about his wife when we were together in the past but when I did find out, I contacted her and told her all about it. He’s now reached out after 3 years of no contact. Texted me and Called me by my name and wanted to know how I was doing and tried to call me. I immediately reached out to his wife and told her again. I just want to know why would he reach out to me after so long?

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Backstory: he got engaged to her and I was pregnant at that time by him and so was she. I ended up terminating and she went on to have kids and get married to him.
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Now he’s reaching out after 3 years
Why would my ex reach out to me after years of no contact?
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