I wouldn't remarry my ex if he arrived with a big red bow on him and a $10 million check made out to me in his hand.
After the first very painful period of initiating the divorce, I regained my sense of balance and became friendly and communicative with him again. At one point, when he was having difficulties with No. 3, she wanted to speak privately with me. Fortunately I was able to wiggle out of what I knew would be a very uncomfortable position for me, that of not leveling with her about any grievances she had against him, as I had to travel internationally the next day and could not risk getting an upper-respiratory disease. She had a bad cough. I knew what her complaints were going to be. No. 2 also had similar grievances.
Anyway, he, with his mammoth ego, thought on some level that he could re-enter my life after the death of my beloved husband. Boy, was he ever way off the mark! But, as I wrote, he was egomaniacal and saw himself in a different light from the one under which I viewed him. I won't explain specifics, but he made it clear at different points in my unattached periods after we parted that he was available.
Never again.