We'd a training session where we discuss work related things and I have a tendency to not participate in them. I just sit quietly and respectfully glean knowledge.

Today we'd one such session. All participants were girls except me and another guy. One of the directors of the company was present along with my boss (both female). For context, the other guy was pretty actively discussing his work related stuff (more power to him).

Typically i hadn't participated much. This possibly triggered the two speakers, though i don't think that it should. During the break the director said "So among the boys only <me> has turned up today." One girl corrected her by saying "but <otherguy> is also here".

Director: "I'm talking about boys not men".

*laughter*

I just smiled, wtf should I have said to a person who's 2-3 levels of hierarchy above me? I'm disgusted with myself for even smiling for those 3-4 seconds. Any tips?

Edit: Thank you very much.