How do I make my ex regret what he did??
You can't - regret sows it's own seed.
If he's done something to regret, he'll remember it before long. If he has no regret, then nothing you do will force it.
show him you don't NEED HIM and can do better WIT OUT HIM.. he will regret it then...
cant force it :(
dont try guilt tripping him either
thats called manipulation
By being mature, and showing him how happy you are without him!
You forget about him, move on, and enjoy life without him...