My Older Brother Has Super Sensitive Nips!? -His Sensitive Spot is Peeking Out-

"Shin, are you feeling it from your nips?" Reo, a library assistant, dislikes Shin Osawa, his overly serious upperclassman. One day, the two of them are working together, much to Reo's annoyance. However, after a small accident, he discovers that Shin's nips are super sensitive...!? Oh god... Ah! Don't..." When Reo touches his nips, Shin's face gets red and he pants like he's been enraptured... Th-that's way too hot!! Moreover, their parents have gotten married, so they're brothers now! Shin moans every time Reo "accidentally" pokes or rubs his nips. His flushed cheeks and watery eyes... are just so hot...! "If I've got such a hot older brother, I have no choice but to do him, right!!?"