I'm working on an app where the user needs to select a gender from a dropdown list. In keeping with the tone of the app, the terminology should be casual – "Male/Female" is too clinical, and "Man/Woman" is too stiff.
One possibility is "Guy/Girl," which matches the conversational style of the app's language. I'm not sure those terms have parity, though – "girl" seems more like a diminutive form of "female" than "guy" is of "male."
Is "Guy/Girl" the best option, or is there something better I could be using?