rule 34 alien arms tied balls big dom small sub bodily fluids bottomless bound clothed clothing cybernetics dialogue dominant duo english text erection foreskin forked tongue frottage genital fluids genitals green penis hands behind back hi res human humanoid genitalia humanoid penis interspecies larger alien licking head machine male malemale mammal muscular muscular male nipple chain nipple piercing nipples nude penis piercing precum predator franchise prehensile penis profanity retracted foreskin sex size difference smaller human text tongue unusual anatomy unusual genitalia unusual penis xenoguardian xenophilia yautja 5390065