Which number is missing?

Three women: one engaged, one married and one a mistress, are chatting about their relationships and decided they needed to spice up their love lives. All three agreed to wear black leather bras, stiletto heels and a mask over their eyes that evening with their respective lovers.
After a few days they meet up for lunch and compared notes.
The engaged woman: "The other night when my boyfriend came over he found me with a black leather bodice, tall stilettos and a mask. He saw me and said, 'You are the woman of my life. I love you.' Then we made love all night long."
The mistress: "Me too! The other night I met my lover at his office and I was wearing the leather bodice, heels, mask over my eyes and a raincoat. When I opened the raincoat he didn't say a word, but we had wild sex all night."
The married woman: "I sent the kids to stay at my mother's house for the night when my husband came home I was wearing the leather bodice, black stockings, stilettos and a mask over my eyes. As soon as he came in the door and saw me he said, 'What's for dinner, Batman?'"