Нимфетомания

Extremely Elastic

The vagina is special, because it isn't designed for sexual intercourses exclusively, it is also designed for births.

This makes the vagina extremely elastic!

The vagina is almost like a rubber band; it has potential room. When the rubber band is in its default state, it may seem pretty small. But as you start to expand it, like stretching it with your hands, it suddenly becomes much larger. When you let go of the rubber band, it transforms back into its default state, without having been modified nor damaged in any way.

This is exactly how a vagina works.

When a vagina is in it's default state, it may seem like a tight little hole, almost like a fragile little tube. In reality however, it has the potential to safely become much larger.

When a female is unaroused, her vagina is almost collapsed, so the walls within the vagina actually meet. But even though the vagina is collapsed, just like the rubber band, it has the potential to be opened and widened up; like when a female e.g. inserts a tampon or going through a vaginal examination.

When a female becomes sexually aroused, her vagina will initially expand some all by itself. And in addition to expanding itself, it's potential room inside will increase as well, making it able to much easier take even larger objects inside.

Due to this very elasticity, especially when considering births, even young children are fully capable of having successful and harmless sexual intercourses with adult males. But only if it's done through proper and regular training, to make a child's vagina accommodated with an adult male penis.

Actually, some of the more experienced adult females actually fist themselves during masturbation, both safely and successfully. And this should be comparable to an average 3-4 year old being safely and successfully fucked by an average adult male. And it can go even larger than that.