Should I contact his ex - girlfriend?

I've been really thinking... I've been dating this man who's 40 and I asked him if he has ever been with a black girl and he explained to me he has and it was a few years ago. She's 3 years older than him... He said that was the time where he put his all in someone... I felt a little bit jealous but at the same time I felt really sad for her and him. He said things were going so great and she just cut him out his life. Blocked him everywhere. He drove by her place just to make sure she wasn't dead and she was there... Honestly that just made me feel so sad. How could she do that to him! He looks like he still hasn't recovered from it... meaning he still really likes her... He showed me a picture and she's really pretty, she has kids that he said he loved. I Know this sounds stupid. I'm not in the mood or rude or mean comments but what if I tried to contact her? Just to understand what was wrong. If she was scared because of how amazing he is. He is an amazing guy for sure... I don't think I'll last with him. He doesn't seem that interested or that invested. I feel kind of miniscule. I don't think he can trust me... but I kind of hope that maybe if I contact her. She'll change her mind about him. Quite honestly though, I'm afraid to do that because he has such a powerful personality, she most likely does as well and will become defensive or angry that I contacted her. I don't know. I know it sounds stupid. But he really seems like he loves her a lot. I know some of you might say don't do it... But I'm a really persuasive person. Maybe she was scared how good he was to her and her kids...