When (in history) did people start dating and having premarital sex (in the West.) For a long time, a girl was considered "ruined" if she lost her virginity before marriage. When did that change in Europe and America?
Your assessment of attitudes towards sex throughout time is a little basic and there also isn't one answer to your question because of how many cultures/time periods are involved. I recommend checking out these FAQs
Matriarchy, patriarchy and women's rights
These answers in particular are relevant:
I'm a twentysomething flapper in 1920s New York City, and I'm interested in hooking up with a man for casual sex. How difficult is it to find a willing partner, and how do I go about it? What are my options for contraception, how difficult are they to obtain and how effective are they generally? by /u/kosmic_osmo and /u/Georgy_K_Zhukov
Zhukov also talked about the sexual exploitation of black male slaves by white women
Continued below