First, he seemed uncomfortable around my friends because he was afraid they were mad at him because of breaking up with me. I guess it's normal.
A friend told me that one day they saw me in the city and he started walking faster and saying "omg she's there". My friend asked him why he was hiding and he answered "she can't see me".
Also, seems like he makes fun of me. He told his group of friends that I was childish. For example, on my birthday, my ex and his friends saw me when one of them said "look, she's there" (I didn't even notice them). One of them (the same friend) said "i'm going to her party later". He answered "be careful, there will be clowns and inflatables" (seriously, I've just turned 17). Also, some people (including friends in common, but just a few) still ask me about him, wondering if I dated him, if we're still dating or if I like him.
My ex told his group that it was all my fault that we broke up, which is party true because I started arguments with him because of my insecurities (I worried too much about him having his own space), which made him get really upset. However, it was him who stopped loving me (he said he didn't feel the same anymore) and avoided me for days before breaking up. Also, he moved on very quickly, seems like he's in love with someone else. So I don't know who's "the best" of us.
All these things are really annoying and I'm not the only "victim". He insulted my sister while talking to his friends, saying "she was a bitch to me, I tried to be his friend but she pushed me away". Everytime he bumps into her, he looks at her sideways.