There is no "one answer" for this question. It depends on the man and what is or is not happening within the marriage.
According to statistics women "initiate 66% of all divorces"
A unhappy man in a marriage is more likely to cheat than run down to the court house. Even mistresses are often warned by their friends "The hubands NEVER leave their wives...etc" (by choice)
I recently wrote a hub regarding Arnold & Maria's situation.
In his case he's claming they pretty much had a "sexless marriage". We'll never know if that was true or if Maria was "rocking his world" from sun up to sun down 5 days a week. (However if Arnold is telling the truth it's unlikely a married man is going to file for divorce because his wife is not having sex with him.)