Younger brother saw his childhood friend having sex with his brother so he forced himself onto her the next day
The female character is very submissive and might be a genderbent. The younger brother is aware that he is smaller and may not bring her as much pleasure, judging by her reactions, but he still tries his best. He couldn’t stop her relationship with his older brother, but he refuses to let her go. The doujin focused more on the younger brother's perspective and only had a couple panels of the older brother.
u/newgame9110 — 3 days ago