Rule 34 Dev - 2023 2boys 3d alien alien_only ambiguous_gender animated aperture_logo aperture_science balls_deep crotch_hugger crotchhugger eyeless gay half-life half-life_2 headcrab loop male male/male male_only male_penetrating margevonn masturbation nonstop_fellatio penis_milking poison_headcrab scientific_experiment scientist shorter_than_30_seconds sound source_request standing video voice_acted vortigaunt watching yaoi|8370732344