[Q: Where did Cable come from?]
Ok, short story. Scott [Cyclops] banged a crazy woman when he thought Jean [Grey] was dead. (This was yeaaars ago.) Crazy woman got pregnant. Baby born, baby got real sick. Only future tech could save him. Baby went to the future, grew up. Baby became Cable, who then came back in time. Then Scott had sex with Wolverine.
Ok, the last sentence is a lie