After having sex for the first time, young women are most likely to feel a) fearful of becoming pregnant and/or contracting an STD b) guilt or regret c) deep love.After having sex for the first time young men are most likely to feel a) afraid that his partner will get pregnant or that he’s contracted an STD b) anxiety about performance c) elation-he finally did it!.What percentage of heterosexuals loses their virginity by age 19? a) 33% b) 50% c) 75-80%.Who’s having the most sex? a) divorced men b) single men or women under the age of 30 c) married couples.How much do you really know about sex? Sure, you know the basics about the birds and the bees, but how savvy are you about all the rest of the stuff that goes on between the sheets? Answer these questions, taken from Pepper Schwartz’s The Lifetime Love and Sex Quiz Book-and see how much you really know.