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2010s 2018 2boys 2d 2d_(artwork) anal animated_skeleton apron ass big_penis bigger_male bigger_penetrating bigger_penetrating_smaller blue_penis blush blush_lines bottom_sans bottomless bottomless_male brother brother/brother brother_and_brother brother_penetrating_brother brothers chinese_text clothed clothing duo ectopenis erection fontcest from_front_position humanoid incest intraspecies kneeling larger_male larger_penetrating larger_penetrating_smaller legs_apart legs_spread male male/male male_focus male_only male_penetrated male_penetrating male_penetrating_male mianpigui_(wqw1201501125) monster monster_boy orange_background orange_blush orange_penis pants papyrus papyrus_(undertale) papysans partially_clothed penetration penis penis_out penis_size_difference penis_through_fly sans sans_(undertale) seme_papyrus sex sibling_incest siblings skeleton small_penis smaller_male smaller_penetrated socks speech_bubble text text_bubble top_papyrus uke_sans undead undertale undertale_(series) unzipped unzipped_pants video_games yaoi

2010s 2018 2boys 2d 2d_(artwork)anal animated_skeleton apron ass big_penis bigger_male bigger_penetrating bigger_penetrating_smaller blue_penis blush blush_lines bottom_sans bottomless bottomless_male brother brother/brother brother_and_brother brother_penetrating_brother brothers chinese_text clothed clothing duo ectopenis erection fontcest from_front_position humanoid incest intraspecies kneeling larger_male larger_penetrating larger_penetrating_smaller legs_apart legs_spread male male/male male_focus male_only male_penetrated male_penetrating male_penetrating_male mianpigui_(wqw1201501125)monster monster_boy orange_background orange_blush orange_penis pants papyrus papyrus_(undertale)papysans partially_clothed penetration penis penis_out penis_size_difference penis_through_fly sans sans_(undertale)seme_papyrus sex sibling_incest siblings skeleton small_penis smaller_male smaller_penetrated socks speech_bubble text text_bubble top_papyrus uke_sans undead undertale undertale_(series)unzipped unzipped_pants video_games yaoi

2010s 2018 2boys 2d 2d_(artwork) anal animated_skeleton apron ass big_penis bigger_male bigger_penetrating bigger_penetrating_smaller blue_penis blush blush_lines bottom_sans bottomless bottomless_male brother brother/brother brother_and_brother brother_penetrating_brother brothers chinese_text clothed clothing duo ectopenis erection fontcest from_front_position humanoid incest intraspecies kneeling larger_male larger_penetrating larger_penetrating_smaller legs_apart legs_spread male male/male male_focus male_only male_penetrated male_penetrating male_penetrating_male mianpigui_(wqw1201501125) monster monster_boy orange_background orange_blush orange_penis pants papyrus papyrus_(undertale) papysans partially_clothed penetration penis penis_out penis_size_difference penis_through_fly sans sans_(undertale) seme_papyrus sex sibling_incest siblings skeleton small_penis smaller_male smaller_penetrated socks speech_bubble text text_bubble top_papyrus uke_sans undead undertale undertale_(series) unzipped unzipped_pants video_games yaoi

2010s 2018 2boys 2d 2d_(artwork) alternate_costume anal anal_penetration anal_sex animated_skeleton ass bigger_male bigger_penetrating bigger_penetrating_smaller blue_blush blue_penis blush blush_lines bodily_fluids bottom_sans bottomless bottomless_male brother brother/brother brother_and_brother brother_penetrating_brother brothers clothed clothing duo ectopenis ectoplasm erection fluids fontcest formal formal_clothes formal_wear genital_fluids genitals humanoid incest intraspecies larger_male larger_penetrating larger_penetrating_smaller male male/male male_focus male_only male_penetrated male_penetrating male_penetrating_male mianpigui_(wqw1201501125) monster monster_boy neck_tie necktie orange_blush orange_penis pants pants_around_legs papyrus papyrus_(undertale) papysans penetration penis sans sans_(undertale) seme_papyrus sex sibling_incest siblings simple_background sitting skeleton smaller_male smaller_penetrated suit sweat top_papyrus uke_sans undead undertale undertale_(series) vest video_games white_background yaoi

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