Advice for my mom???

So my mom used to date this guy. My mom, sister, and I lived with him for quite some time when I was younger. They didn’t stay together and he eventually got married. They stayed good friends though. His wife eventually tried to murder him by shooting him in the head. He lived though and is just fine. Obviously they are now divorced.

Now, my MOTHER IN LAW is chasing this man trying to date him. She took him to dinner last week I guess. He doesn’t really like her though. He was friends with my father in law for many years and my father in law passed away 3 years ago. She had left him a year before he passed.

This guy wants to date my mom again though and my mom wants to date him.

My mom is just worried it will make drama between me and my husband. I think my mom has right to date him if they want to date and my mother in law is a big girl and will get over it.

Thoughts? Advice for her on how to approach the situation?