i need advice!

I don't mean to be rude, so forgive me, but why do you want to be friends with someone who won't respect who you are and treat you like a friend in the first place? This is pointless if you want to be friends because he doesn't know the meaning of friendship, if he goes and dates your best friend, there is a code that says best friends are a no-no, he has treated you so unkindly and you frankly are better off without him. If not for yourself, think how your boyfriend would feel knowing that you want someone like your ex as a friend. Having an ex as a friend is okay if they genuinely respected who you are and care for you as a friend and clearly this guy hasn't done that for many occasions already.

I'm a guy so believe me when I say, the reason why he likes you now is because you are with someone else and he does not want you back, he just wants you because stupid guys only regret what they have lost when the thing they love is gone. You are so much better off with your boyfriend and you should be happy instead of allowing your ex to taint that by making you stressed out.

Trust me, this friendship is gone, you can be acquaintances but no good will come from this if you try to be close to your ex. I have seen this so many times to so many girls that I hope to somehow spare you from the heartache of it. Think about this, if you extend the olive branch of peace now, do you really think he will get over you? I highly doubt so, so I suggest you leave him alone for the time being and let him sort out whatever the heck insecurities he has inside of him. You are in love with someone so you should be happy, if your ex talks to you, talk to him back but always keep a distance. I've met guys like these before and the minute they find another girl they will leave you alone, it's kinda predatory but it applies to this situation as well.