I think if I hadn't closed the door permanently, I would have been too smug and unbearable for him to be around. His exact words were that he could find greener grass than what I offered.

So far,I do not think he has found his greener grass if he has had to switch to searching for one night stands. The feelings have been bittersweet because he preferred the thrill of the chase instead of the stability I offered.

The best revenge is to live your life to the fullest. Your Ex will regret letting you go and will start to pain shop by looking you up. There are dumper vs dumpee timelines that are floating around on this and on the Exnocontact sub. From my experience, they do seem to be true i.e. your dumper will be hit with regret after you no longer want to take them back.