My Wife Might Be a Hentai.

Although I was a high school student, I married my childhood friend for a certain reason. It's not like I love her or anything like that, I even considered breaking up with her. However, we got married... Since we're always together and get along fairly well, I said, "How about we get married?" "Sure. If all goes well, we don't even have to get a divorce." This is how the newly-wed life began. At first, it felt a little strange, but it wasn't so bad... "Here, say ahh! Ehe, is it delicious?" ...

Ore no Oyomesan, Hentai Kamoshirenai began as a web novel on Kakuyomu under the title "Osananajimi to Okuru Amaama Shinkon Seikatsu!" (幼馴染と送る甘々新婚生活!), and has been published in print by Kadokawa under its Fantasia Bunko label.