It is easy to avoid casual temptation with infrequent encounters. Not as easy with a second female companion in the house if the cheaters lover life stinks and maybe even if it is good but there is lots of chemistry with the third party. Maria Shriver completely lacks a sexual spark and always has. It is easier to pay the maid extra money to go along quietly. She may see advantages in that for the offspring. The treats for her mean enough that she will be more likely to remain quiet than someone of more means or access to a man with means who will actually take her on as a partner.