I have always interpreted this song as the singer being the blanket. "Just because we are married, don't mean we can't sleep around" suggests to me that the singer doesn't mind being used for a bit of fun. It suggests ( to me anyway) that she doesn't mind being led down and used. I'm probably miles off the mark but I often consider that when friends ask for casual sex. " I don't want you to just be a blanket on the ground".