You should probably tell her........No. Some of them? Sure. Hell, even a majority of them.
You have to remember how easy it is to start a side relationship these days with some "old flame". Some modern women just get F'd over by that time and time again. Women also aren't apt to jump right back in after something like that. So some just "slip through the cracks".
I was luck enough to find one of them. Is she perfect? No, but who is? She's like nobody I've ever met before.
Z