You were talking to one of the recruits, teaching them a few tricks and giving advice when you two started getting off track and ended up just having a friendly conversation.

You were known as a very nice, friendly, polite person who is often careful of what you say as to not hurt someone else's feelings... So when you made that dark humour joke your task force -who had been standing behind you without you realising- was very taken aback.

You heard someone clear their throat behind you.