There was a pretty hilarious exchange in Mass Effect 3 about asari and gender. They're humanoid blue aliens that seem to have female secondary sex characteristics, but they are mono-gendered and don't identify as female. They can reproduce with any gender of any species, and when two asari mate, only one of them gets pregnant and actually has the baby (the mother), and the other is known as the father. The exchange I mention is the main character (Commander Shepard) expressing confusion about the terms "father" and "mother", since he assumes that asari gender is equivalent to human female gender.
Note that there's a bit of (hilarious) profanity in the video: