Fugainai Koi

Yukito's love for his older childhood friend, Keiichi, has only grown more complicated, and has led him to have physical relationships with several men. Yukito has led a debauched lifestyle, but after a few years, he meets Keiichi again. For Keiichi's sake, he resumes his role as the childhood friend. However, one night, when Keiichi comes over to stay, Yukito's sexual desires causes him to masturbate while thinking of him. He meets a sex friend one day without Keiichi's knowledge, but unexpectedly, he was discovered...?!

(Source: Kadokawa, translated)