My advice is this.
You don't enter a relationship worrying about whether it's going to work or not, if he's going to cheat or not, if he/she still loves someone else or not.
You enter a relationship to see where it goes, because you like each other and where ever it goes it goes.
If you take that attitude, there is no room for jealousy, no room for looking for red flags and no broken hearts.
If he is a gentleman, sweet, really good then focus on that and give that back.
"I feel weird he was 31, she was 44".
That's not much of an age gap, he was mature, she was mature, her more than likely more mature, eventually it didn't work out but they formed a good bond, therefore, friendship possibly a lot of respect.
You are 30, almost, he is 46, kind of identical don't you think? Only the other way around.
So you never know this could be a match made in Heaven.
Sounds as if you are worried that he left her because she is 60 and he is only 46, now wants someone younger.
See how when you over think instead of enjoying what you have and seeing where it goes, your mind questions everything.