of all women to cheat with, it''s one with two kids already

foolishness!

and he will probably be paying their school fees and taking care of their bills while his own children is left to suffer.he foolishly thinks he's punishing his wife,

kennybabs1980:
Chuks is a great guy, a good friend of mine in my office. He's happily married as far as I'm concerned. His wife is a school teacher and they have two kids. But I noticed that a particular beautiful lady comes to check on him in the office at least once a week. I asked him about the lady last week, he said she's just a friend. When I probed further, I discovered that the lady is a single mother of two and works as a nurse. That's last week.
Today he called me by himself and told me he's dating the lady and that his wife caused it. He said his wife has timetable for sex, he can't touch her at anytime he like, she complains a lot and tells him sex is not food. He said there are times she won't allow him to touch her in a whole month and that this causes a lot of arguments in their home incessantly. He said he made up his mind to stop this incessant arguments this year and therefore went for this beautiful single mother who has been satisfying him sexually since January. [b]I told him I didn't agree with his solution to his wife's attitude if its true [/b]and he told me he had peace since he ventured outside his matrimonial home to get regular sex and that his wife hasn't ask from him since he stopped asking her for sex since January. Since I ain't in his shoe, I couldn't really prevail on him to stop?
Is this a genuine reason for adultery?
Can't he make more effort to sort things out with his wife?
Can't this strange lady cause trouble for him in his family?

@bolded. So what practical solution did you actually come up with that you think you can agree with?

Personally, because of your last point, I would have preferred that he formalise his marriage to a second wife. But due to oyinbo religion, some men dismiss that as a solution, so adultery/fornication is the only other option.

Or do you prefer that he divorce the first wife first?

There is no sex on demand anywhere except you are paying a hooker. Very soon the side chic will get comfortable and start acting up. Sex will now become a weapon. Will he cope with all her attitude and drama then?
With age comes realization that sex is quite overrated. You may have to adjust and start taking it when you see it, especially when you consider the other drama associated with just getting it.