I have it! I have the question. Now you have to answer me once a...
Stan: I have it! I have the question. Now you have to answer me once and for all! How come I haven't gotten my period yet?!
(everyone is speechless)
God: My child, you are a boy. Boys do not get periods. That is only for girls. You're friends were bleeding a little bit out of their asses due to an acute colon infection, and you're friend Kyle simply lied about it.
Kyle: Hey, how'd he know that?!
God: You will hit puberty when the time is right, but you will never have a period because you are a man with titties.