I'm learning

Today the kids were working pretty quietly, save for some soft whispering between adjacent students. Out of nowhere, one girl says to another (loudly, so the whole class could hear), "It's not safe to swallow? To swallow CUM????"

I said nothing to this and nothing came of it (pun not intended). They were just testing me; if I correct them and say that it isn't unsafe, they'll either ask me how I know or try to start a discussion on that matter. If I asked them to quiet down, the girl who spoke out would defend herself with a more detailed restatement of her question, including probably my educated opinion: "You're a teacher, is it true that..."

About a year ago, I might have done either of these things. But I'm learning.