See subject. This is, in typical GQ fashion, a spin-off from a thread drift of How common is female nipple hair?
I doubt it occurs in more than half the population. Maybe slightly more than half, but that would be it.
Since sex (as in sexual intercourse) is usually involved, I’ll guess it happens in considerably less the half the population.
No doubt true, but sexual intercourse is usually under-reported, so it could be close to half.