I've seen a few married couples before. Sometimes the wife knew I was being paid, other times she did not. Sometimes I saw the husband alone as well either before or after (usually without the wife knowing about it). One time I saw a professor at a prominent ivy league school and his wife. The wife was unaware I was being paid (the money was hidden in a tissue box in the bathroom), and I was asked to play the part of one of his grad students who had a crush on him.