People all have choices, they can make. If a married man wants a girlfriend he shouldn't be married. And any women who has a desire to be with a married man, may be really sick in the head and need some counselling to deal with her issues. Divorce, or work on your marriage those are your options. No girlfriends and nonsense. Your unhappy?... You can change your life, live the way you were intended to live, nourish your spirit. Don't create more chaos in an already chaotic situation that won't give youa solution to your problems.
As long as his wife doesn't find out, it's is something I would not recommend
Not that I know of in less his religion permits it which not may do!!!
It's not right.