COPENHAGEN — Twenty-five Danish 13- and 14-year-olds gathered in a circle to talk about sex. This was going to be awkward.

One student surveyed her red nails while a classmate checked his cellphone. When the discussion turned to masturbation, a girl pointed across the room toward a boy who was already chortling, and then she started to cover her own giggles by cupping a hand over her mouth.

“It’s O.K. to laugh,” said the instructor, 29-year-old Andreas Beck Kronborg, who looked young enough to be an older brother. “We’re going to talk about stuff that’s embarrassing.”

Recently, Sex and Society, a nonprofit group that provides much of Denmark’s sex education, adjusted its curriculum. The group no longer has a sole emphasis on how to prevent getting pregnant but now also talks about pregnancy in a more positive light.