Most Helpful Guy
You could try things that might make him jealous, but the odds are not in your favor by doing any of that.
Instead, you can stop thinking about him, since he has caused you a lot of pain and start thinking about yourself. Make yourself the main focus and not him. Treat yourself to activities you like to do or learn new hobbies you can immerse yourself into. Join activity groups, where other like-minded people will enjoy getting to know you. Get into shape (if you're out of shape) or workout more, as exercise can release a lot of endorphins helping you feel better.
You'll have so much going on and meet so many people you'll find yourself in another relationship with someone who shares a lot more in common with you than your ex.
You'll have healed from this breakup, moved on and will be happy once again. Whether your ex sees that or doesn't is irrelevant, because he's chosen not to be a part of your life. So, let him go and let yourself thrive with all that you are and can offer someone who appreciates you and wants to be with you.
Like I said, he may or may not regret anything, but you'll be so much happier with your new life and will be even more glad you're no longer with an ex that didn't appreciate you the way your new lover does.1