>>1335882>The picture is purely illustrative of the phenomena, it's not "to scale".That's putting it mildly - for the scale in your picture to be right the entire uterus and surrounding structure would need to shoot up into a woman's duodenum every time she gets horny.
In actuality the vaginal canal is only about 2-3 inches in a relaxed state and only extends to about 3-5 inches at most during arousal, it can be stretched beyond that, but at that point you're physically stretching the tissue beyond it's normal limit.
Basically unless you've got a fucking micropenis you're in no danger of failing to optimally penetrate.
