rule 34 2015 abs anthro balls big penis canine clothed clothing cybernetics cyborg duo english text erection fangs frottage gorath group17 hal greaves half closed eyes humanoid penis hybrid looking at penis looking down machine male mammal monochrome muscular navel nude open mouth pants down partially clothed partially retracted foreskin pecs penis precum retracted foreskin sex shirt simple background smile standing tank top teeth text uncut white background yaoi 1987399