I totally know what you mean by "Stop this damn ride".
While I was still in the house with my wife, and she was being unfaithful, I had this dream: I was in the car, everything was dark, the windows were fogged, the brakes weren't working. My wife was next to me in the passenger seat, my kids were in the back. the car was racing along backwards in the dark, and I was trying to steer, trying to see, pumping the brakes, and nothing I did was stopping the car. It was totally out of control, and I was in fear of a crash, and I was so upset that nothing I did was making any difference.

Sound familiar?

If it were me I would bring it up. "The neighbors are concerned..." You'd have to be super gentle. But firm.

This is just me, though. I would not tolerate that, ever.
And, who the hell wants to be married to a sucker? With every time she deceives you, she loses respect for you. If there is any hope in salvaging this, you have to draw a line.
(This is just me)