Ladies. What does this mean?

When a woman puts her feet on your crotch while out at dinner in a resturant? The lady im dating does this all the time, and ive had many other do this as well even with high heels.... One night i was laying in the floor she walks up between my legs and put her stiletto on my crotch and was kinda stepping on it while smiling at me... I liked it but what was she doing this for?