Second one! Cross and Killer are(at least from my knowledge)canonically rivals, I believe? They're my two favorite Au's, but how would they act in a poly? The idea of them fighting over Y/n all the time is kinda funny...
*Cross and Killer absolutely fight over you, or rather, who gets your attention/affection
*You have had to stop them on more than one occasion, before they caused any problems
*you cannot spend more time with one over the other, or the other will get very jealous
*You try spending one on one time with both of them when possible, though
*Killer is more affectionate than Cross, but Cross is more protective of you
*of course neither would allow anything to ever happen to you, though











