Clearly, You know nothing about Vatican Roulette!
After the fourth boy was born, my mother moved to that technique. Worked good for her ...
BTW, Vatican Roulette is:
rhythm method. n. (Gynaecology & Obstetrics) a method of controlling conception without the aid of a contraceptive device, by restricting sexual intercourse to those days in a woman's menstrual cycle on which conception is considered least likely to occur.
Then too, I have had Mistresses who insisted on receiving Oral Pleasure two or three times a day. No need for contraception either.
So I forgot your question ... cause I am busy worshipping Her Temple!
Got my second paddle! Finally! :-)
Heck I had one in 2010 .. now in 2013 another! Yes you can say, i am just a gifted slow learner!