I call people by their character's gender. If your gender doesn't match, you can correct me and I'll use the proper terminology from then on, no big deal.

Slightly off topic, but is it offensive to girls when people refer to them as "guys"? Context: "I'm gonna hang out with the guys!" Where in this case, "guys" refer to a group of people with male and female members. Does being lumped into the "guys" catch-all offend the ladies? I'm legitimately curious.