Sexually repressed cultures tend to generate very bizarre myths about sexual matters, including of course female anatomy. But with less repression comes less anxiety and hence people (usually but not invariably males) feel less need to create nonsensical tales. Hopefully the USA will continue its (very slow and gradual) trend towards more European norms so that one day these locker-room fantasies will no longer be heard. In the meantime I can say from experience that you’re absolutely right Octavia. I’ve known many woman who have given birth naturally multiple times and none were “loose.” Furthermore, as the vagina is quite a complex organ, a great deal depends on arousal and the woman’s proprioception. Women who are in tune with their bodies have a far greater capacity for utilizing the various muscles etc. that surround the vagina and clitoral mass (most of which is inside the pelvic cavity).

Speaking from personal experience, some years ago one of my partners and I were having a foursome with two other men, both of whom were significantly more endowed than me (I’m about average in that regard). Each of them “went first” and when it was my turn my partner gripped my penis with her vagina just as tightly as always (and that was in fact very tightly indeed) despite moments earlier having accommodated two much wider penises one after the other. If a woman’s vagina can thus adjust in a matter of seconds, it’s clear she can adjust to events like childbirth.