1, are you loyal to your partner?
2, you will have a lot of dissatisfaction with your other half.
3, will there be other people, the opposite sex often harass you, but you don't object.
If there are the above points, there is a great possibility of having an affair.
Your spouse is the same anyway.
In fact, two people together should trust each other. Not mutual suspicion.
I answered in my heart, I hope it will help you. If it feels good, you can adopt it.