I have witnessed orgies. They were not uncommon on WHO tours. I did not participate. To do so would have been outside my job description.
I was introduced to sex around others at drive-in theaters in high school in Pittsburgh during the early sixties. Mind you, sex was more in it’s “touching her bits” phase and nothing remotely full blown but I was clearly two or three feet from another couple during the action. The experience was dangerously not “Methodist” but it was hardly “Roman”.