The quip about three fingers when the girl says “two’s good” randomly reminded me of an old “Ask Dan and Jennifer” video I recall watching. They were a couple who made videos with sex tips. In one video Jennifer was explaining the proper technique for massaging the g-spot with the “come hither” finger motion. Dan chimed in with “you can use two fingers if you want to” and without hesitation Jennifer replied “or you can use one.”
I made a mental note to use one finger.