When I tell someone they're not dressed appropriately for wherever we are, it's not about their sex life. It's about them not respecting the setting enough to dress appropriately. They can have as much sex as they want, regardless of their gender or the gender of their partner(s), as long as they don't do it in front of me. But they really shouldn't wear revealing or sloppy clothing while teaching Sunday School, etc., and I am not sorry for calling them on it.
Sincerely, Stop making it all about sex.