Rule 34 Dev - 2d 3boys bed blush blushing breathing_heavily dialogue ectobody english_text female_genitalia gay gay_sex grabbing_arm humanoid looking_back male penetration sans sans_(undertale) sex slimeybonez smile straddling tongue_out underlust_sans underswap_sans undertale_(series) undertale_au undertale_fanfiction waving|10705784448