When 2 bros sit side-by-side facing forward (sometimes in a moving vehicle), and use the arm closest to one another to reach over and give the other a hand-job. As this happens simultaneously, their arms cross each other, forming an "X," hence the term X-Men.
Dave and Josh were totally just caught playing X-Men in the front seat of my dad's car...
A bunch of overly muscular mutants who can't have sex because they might kill each other by means of explosion/touching/stabbing/electrifying/freezing/burning etc.
(N.) A word to be used much like a pronoun, to replace a peron, place or thing.
When I got up today, the first X-Factor I did was to take an X-Factor. Then I took a major X-Factor, did way too many X-Factors, and finally at night, before I went to sleep, I did a MAJOR X-Factor! Oh man, the X-Factor was the most X-Factoringest X-Factor ever.