Do you mean work settings? I think traditionally Sex has been a staple of social settings; it's why a non-trival amount of people play novice sports (to meet future spouses).
Generally best to avoid talking about the specifics of the actual acts when in polite company.
Sex, Politics, Religion were the traditional ones to avoid. I'd also add 'childcare/how to raise children' as another one that can easily escalate/some people have very strong opinions on.
