Why not just get a divorce
Well, a lot of people would think that if you’re going to have an affair then you may as well just get a divorce. It’s a reasonable objection to the whole bout of shenanigans. The other option is to seek couples therapy. Everyone is going to be a case by case scenario, and I have no formal qualifications with which to offer legitimate advice.
My personal view is that if you’re unhappy with the person you’re with, you should find out why. Then do something about it. Depending on the type of problem either trial separation or couples therapy can be a very worthwhile thing to do.
Advice specifically for men. If you’re thinking of cheating because the fire of sexual passion has gone out, maybe get a gym membership for six months and get cracking. The reason the passion may no longer be there is that you’ve put on a few kilo’s (or pounds for those still back in ye olde imperial land) and your not quite as sexy as you think you are.
Get yourself into shape and you might find that your current relationship may re spark in the ways you want it to, and if it doesn’t, you’ve given yourself far better odds at picking up a mistress on the side.