Could be a number of things, one told me her husband never tried anything kinky, there was one I met that had been married to her husband since graduating from high school and had never been with anyone else,
She was friends with a female friend of mine, she came with us one night when we went out to a club, once I got her on the dance floor she went wild, I wound up taking home with me and my friend covered for her telling her husband she spent the night at her place,
Most of the ladies I met either wanted to try something new or were just plain bored of being the good wife.