He is a tall, dark, educated, employed man who makes a lot of money. He works long hours including some holidays. He travels some on business. He is single and you are the only woman in his life. He visits you and sleeps with you when he can. He calls and emails when he is away. He sends you romantic cards on special occasions.
What's wrong with this picture??? He is actually married and seduces women as a hobby. He maintains an apartment for himself in one city and an expensive home for his wife and grown daughters in another city. He seduces women on the Internet as a hobby. He has a dozen mistresses in a dozen different cities. He buys romantic cards by the dozen. His calendar is filled with dates to mail them.
He doesn't work long hours or holidays. He just tells you this to explain his absences. His wife found out about his philandering years ago and no longer cares what he does. They have an arrangement that he likes. He has no intention of getting a divorce.