Baka na Inu hodo Itooshii

Unemployed and with no fixed address, Meguru Watanuki always shows up at his friend Kaname Tatsumi's door whenever he finds himself flat broke. Meguru is in love with Kaname, but has no intention of telling him, lest it ruin their comfortable relationship. Then one day, while doing a delivery job offered to him by a shady stranger, Meguru lands himself in hot water and is force-fed some very dubious drugs. Though he manages to make his foggy way home, he is unable to contain his drug-induced excitement, and ends up assaulting Kaname in his sleep...!

(Source: Fusion Product, translated)