I found out where "bae" comes from and claimed that alone was why I'm glad to be in class today. They laughed. This happened a few times. A question or answer would pop up, and we heard chuckles, the sound of doorways approached.
I had no idea, specifically, where this all was going but I'd ask "Why the chuckle?" (I'd ask with a smile, by the way. Not my usual semi-scowl (my bad luck with the downturns in my face).) If they couldn't answer, good enough. Every bit of reflection on language helps us use it, I've always claimed.
Maybe that's just hope minus doubt.