Yeah! The baby-boomers were chaste as the wind-driven snow!
I was born in the late 30's. In college in the Middle West many of us lost our virginity or were sexually active. On the whole though it was not the first date, and not unless we thought we would continue to date the person. Not like "hooking-up", although as one accumulated several years of experience and friends, it might become "friends with benefits". In high school in the East it was not as common, although some girls from working class families had a "reputation." One 15 year old college track girl got pregnant by her steady boyfriend. It was a bit of a scandal
My mother was in college in the late 20's. She and her friends used to go from New Jersey to "speak easies" in New York City in the Village. I doubt she was a virgin when she met my father.
Actually some of us were and some of our children are. Shock of all shocks!