Should I Tell

I have been involved with a married man for about 15 months now. It started out with him pursuing me and me saying no but after a month we ended up sleeping together. 2 months in I started dating someone and he became jealous, he confronted me about being in love with me and not wanting me to date. He said he was going to leave his wife and move in with me, we even set a date. The closer we got we decided to push it back a few weeks till the end of our kids bball season but before school started. During that time he accompanied me to my surgery and then took a wkend vacation where he met my brother, s.i.l, and my mom. Shortly after that he went to his wife's family reunion and a week later took his fam to Vegas to meet his brother. All this he promised he wouldn't do. This lead to us arguing about his lies. We stilled talk and were intimate. Come Aug his wife's cousin told her she had seen his vehicle at my house and took pics for her. She even brought her by my house once but I was at work and she has came by a second time when I was at work. I pushed him away but my heart was to far in that I get weak and do not stand my ground so the cycle continued.
Moving forward to the new year I finally put my foot down and said no more. I met someone new and dated for a short while (4 months) before that bit the dust. Welp as soon as that relationship ended unfortunately the cycle began again with the married guy. He said he wants to be with me but he is scared of losing everything again (this will be his second divorce).
We both have school age kids. He has 3 grown kids and 5 grandkids. We live in a very small town so our older kids go to the same school. Our younger kids have played ball against each other. He is very involved in his kids life cause of his wife's schedule so she is gone often. He talks negatively about his marriage but I know their is a side I dont know about. He has always told me that he was considering divorce before I came into the picture. And the kicker is we work together! I have been trying to move locations but since we have been involved he has been trying to move to the same location.
So here we are now. He still says he truly loves me and wants to be with me but of course when I ask him to put a date on it he can just say it's hard.
At this point I love myself enough to walk away and told him to do the same but he won't. He wants to be friend which we are good at but that ALWAYS comes with the occasional sex. I told him we cant be friends, not even talk as long as he is married. I also told him I would tell his wife if he doesn't let me be. My logic behind that is o truly believe she WILL NOT leave him cause she knew it happened plus this isn't the first time she caught him. I figured she can get him in check and/or he would be mad enough to leave me alone. As much as I would love to be with him I do know this is not the way and that is not my intent behind it.