Rule 34 Dev - 3boys 4boys anal_insertion anal_object_insertion bar_censor bara big_penis blindfold bound_ankles bound_penis bound_wrists catrasche censored clothed_on_nude cmnm cock_and_ball_torture cum cum_in_container cum_while_penetrated dark-skinned_male dildo dildo_in_ass electrode electrostimulation erect_nipples experiment facial_hair gay holding_penis labcoat laboratory machine male male_only male_urethral_insertion malesub milking mouth_open multiple_boys multiple_males multiple_subs muscle muscles muscular nodules nude penile_insertion penis penis_milking penis_milking_machine penis_pump pointless_censoring science scientific_experiment scientist sex_machine tan_skin testicle_expansion tube_in_penis urethral urethral_insertion yaoi|1456506496