http://www.mangago.me/read-manga/romantic_pornography/sa/d_v-1-chapter-4/pg-2/sauce?
Author is Narusaka Rin. Don't know which story though
thank you!
In case you still didn’t find the story here the link. https://www.mangago.me/read-manga/dekiai_keiyaku/
http://www.mangago.me/read-manga/romantic_pornography/sa/d_v-1-chapter-4/pg-2/
sauce?