Women enjoy complaining about the the double standard. They claim that it is something imposed upon them by the Patriarchy. And that because it is a double standard, it is unfair. The reality of the situation is a bit more complex.
When it comes to marriage, men prefer chaste women, or in modern times, ones that are as chaste as possible. This due to the issue of uncertainty of the paternity of any children coming from a marriage. A woman who has not fooled around in the past is assumed to be a good candidate to not fool around in the future. And thus a man can have greater confidence that the children she bears are his. This is what a man wants, and sluts do not fit the bill.
Women on the other hand, value perceived quality seed highly. The thought is that, once she does obtain that seed, she can use deception and her feminine wiles to obtain sustenance. If she can pull this off, then in her mind she has won. One question remains however, how to determine which man has the quality seed (hint — crowdsourcing). Especially in situations where much is hidden and there are many unknowns. One shortcut that might be good enough is to determine which of the men the other women are seeking. Why not put the knowledge of other women who are seeking the exact same thing as you are to good use? And indeed women do. When said and done, it only takes five minutes (or less) to get what she wants. Furthermore, it matters little to her that other women have utilized that same source of seed. She got hers, so what else matters? In short — these men have long sexual histories and women are attracted to them because of it, not despite it.
So what is the double standard? Men demand chaste women for marriage, while women are more forgiving in this regard. That is how it often expressed by women; an expression that casts them in the best light (much better than cuckolder I might say). Because, of course, forgiveness is a virtue. Still, in the end, we see that the double standard is actually a joint venture between men and women; it is not something created out of whole cloth by the Patriarchy.