I’m curious to know what it means. I grew up not even being allowed to say “oh my god” because it used the name too casually and this was “in vain”. I don’t know if that’s just my family/faith though. I always wondered why.
Do not take the Lord's name in vain refers to the idea that you as a lowly mortal human cannot possibly know what the Lord is thinking or says so don't say that God wants it, or that he curses the gays or anything like that. It's basically, don't presume to speak on his behalf.
We can swear during sex. Y'all can only say frick.