Rule 34 Dev - !!! !? 2010s 2boys 2d 2d_(artwork) almost_caught animated_skeleton ass bathing bathroom bathtub blue_blush blush brother brother_and_brother brothers bulging_eyes cheztnuts closed_eyes clothed clothing comic comic_page comic_panel completely_nude digital_media_(artwork) door drooling duo edit edited english_text fingering fingering_self hand_behind_head holding_clothes holding_clothing holding_object long_image male male_masturbation male_only masturbation moaning monster multiple_images nude open_door papyrus papyrus_(undertale) rubbing sans sans_(undertale) sequence sequential shocked shouting skeleton solo_male speech_bubble surprised sweat talking_to_another text text_bubble third-party_edit tumblr undead undertale undertale_(series) video_game_character video_games walk-in water yelling|1037228