Rule 34 Dev - 1boy 2010s 2017 animated_skeleton artist_signature blue_blush blue_tongue blush bottom_sans bottomless chinese_text immolationyyx monster pixiv_id_9733540 sans sans_(undertale) shirt_only shirt_up skeleton submissive submissive_male sweat text tongue trembling uke_sans undead undertale undertale_(series) white_background|1016446