Ana no Aku hodo

Oda, a salesperson, participates in his company's remote drinking party for the first time. However, he forgot to hang up the video call before violently masturbating with his ass. The junior mechanic, Kuroishi, witnesses this and when Oda realizes there's still someone in the call, Kuroishi confesses saying...?

(Source: Takeshobo, translated)

Note: Includes the one-shot "Chikubi ga Yowakute Ikirenai (乳首が弱くてイキれない)" and two extra chapters.