Aishite Hoshii no wa Ore ja Nai noni! BL Game no Akuyaku Reisoku ni Tensei shita noni Kirawarenakute Komattemasu

One day, Arthur realizes that he's been reincarnated as the villain in a BL game. On top of that, he remembers that based on the plot of the game, he only has endings like the "Imprisonment Ending" and "Tentacle Ending" waiting for him! With no other option to save his chastity and life, his only way out is getting his fiancee to get with the protagonist! Dragging along his trusty servant Edgar, he tries to craft up schemes to get the two of them together. But, rather than being hated as the villain, he starts raising BL flags of his own?!

(Source: Kodansha, translated)