Beef curtains are probably due to genetic reasons though. Vaginas don't get permanently stretched from sex.
they're not permanently stretched.
if a girl has beef curtains (assuming she doesn't have a child), it's probably because she gets fucked a lot on a regular basis. If she stopped, it would go back to normal. but she if she is getting it VERY often, they'll flap in the wind.
This is why the finger test is a good idea. If you can put one finger in and there's slight pressure, you're good to go. If you put one finger in and it feels like a pale of warm water, bail out.
Unless a girl is a super skank, there should still be slight pressure with one finger. Because it takes a while for it to loosen up. It doesn't mean she's super tight, it just means she's getting warmed up and she probably hasn't been fucked in the last 12 hours.
This is a better way to test how slutty a girl really is. Finger test for life.