Oh I don't know what I was thinking. I was thinking a wolf whistle was literal at first, as in a whistle designed to attract actual wolves, then I thought it was called a wolf whistle because it was designed to attract older ladies that are considered wolves, kinda like cougars, but then I realized that's not even a thing really and looked some more and realized a wolf whistle is called a wolf whistle cuz of some fucking show back in the 40s.
Today, a wolf whistle directed at a person is sometimes considered a precursor to sexual harassment, or a form of sexual harassment in itself. The name comes from the Wolf character in the popular 1943 Tex Avery cartoon Red Hot Riding Hood who whistles in this way at sexy female character Red.
So, to be honest, wolf whistles are in fact very, very dirty.