How do I find a fwb.........?

I want an fwb. Don't judge, cause you don't know what its like to be with the same person for 15 years. It gets stale. Its like having steak (which is great) every single day. Even though its great, you want something else after a while. And, I'm feeling like I'm running out of time. I got stuck with my wife and never got to finish sowing my wild oats. Besides, most couples cheat in our modern world and its no big deal. We got into a big fight about a week ago and it seems we are just not compatiable. I will continue to support her and our daughter as much as I can. But, that feeling is gone. We don't even kiss anymore.