This is something that virtually always happens when people get together and start drinking in halls kitchens/people's houses.
They buy cheap drinks, start drinking, turn to drinking games (because that's usually the quickest way to get people drunk for a night out), and the topic of the drinking game would always - without fail - revert to sex. Playing games like "never have I ever?" and the statements would always be about sex or sexual acts. Which really embarrassed any virgins who were there.
Or it would descend to some sort of drinking/stripping game where people have to take off items of clothing (again sexually related).
Was this other people's experiences and why does it have to happen?