I’ve often wondered how guys get away with this kind of thing. It seems to me that you can only do it if you can deal with a lot of cognitive dissonance, and your spouse is not very observant, or has low self-esteem and won’t question it. Once the dissonance gets too great, you confess. Or if the spouse is observant and has enough self-esteem, they confront you.
I don’t know if it counts if you do something with someone while you’re on a business trip. Is that a mistress? Seems to me a mistress is a long term thing, where you’re having an affair, not just a one-time thing. But if you want to hide it, you can go on a lot of “business trips,” or you could meet in the afternoon, or you could work late a lot. Or go running. Or out with the boys. Take a class. Anything that gets you some alone time for long enough to meet secretly.
Generally, I’m of the opinion that a mistress is a sign you need to work on your marriage. I wish guys would have the courage to try to deal with marital problems before they have an affair, but I totally understand when it doesn’t happen. People can be such wimps when it comes to working on difficult issues in relationships, when dealing with those problems might turn your life upside down. It can feel easier and safer to fool yourself into thinking everything is ok enough, or it’s endurable, and you’ll get what you’re missing on the side.
Marriage may be sacred, but it don’t come with no manual, and a lot of people fall for the myth of “happily ever after.” There’s a lot of shame in admitting the ever after isn’t happy. You often can’t admit it to yourself, much less to anyone else. If you can’t do that, you can’t work on it. Shame plays a big role in both creating affairs, and in ending them.