Most Helpful Guy
I've only had one "ex." (To be honest I hate the term because of the negative connotations that go with it.) We parted on good terms and she remains one of my all time best friends. I'd be an idiot to give that up. My advice is, don't give up your friendship simply because he's your "ex." You were in a relationship and now you aren't. You're supposed to break off your friendship simply because you were closer before? I think people who part on good terms should never just give up the relationship (in terms of friendship). If people call you foolish for doing maintaining the friendship, that's their problem. Don't keep yourself from a good thing just because it isn't part some social norm.
Most Helpful Girl
I only stayed friends with my first ex, when we were 18. We dated for around 5 months. When we met we didn't even got to know each other, we just hooked up the very next day and made our relationship official, lol. This was because of me, because I was young and I thought that's how it goes. I was a student and he was a street artist. I was very controversial and shy, and he was very open minded, outgoing and confident. He was 2 years older then me and he already slept with bunch of girls. He was also drinking alcohol and smoking weed at the time, while I was not. Well you can imagine why it didn't work out. I started smoking weed with him and skipping my classes (initiated by me), and he felt like he is a bad influence for me. We had a nice talk about it all and decided we should breakup because he wasn't ready to change because of me. We enjoyed each other's company and even though he had terrible habits, he was a great guy to me. We promised to stay friends and now 10 years later we are still close friends. He's one of my best friends. :)
P. S. He still didn't change a bit. :D