Rule 34 Dev - 1boy 1girls 2d female female_focus female_sans humanoid male male/female novafruity oc penetration rule_63 sans sans_au sans_oc sex straight tagme undertale_(series) undertale_au undertale_fan_character undertale_fanfiction undertale_oc unseen_male_face vaginal vaginal_penetration vaginal_sex|6906293952