Kigeki wa Koi de Shinkasuru

From Nakama:

Hane Hajime, who spends his life lazing around and being dependent on others, is twenty-two years old. One day, having lost his way, he wakes up in a blood-stained bed, with the lower half of his body in full view and his rear end stinging-not surprisingly because he’s serviced a pair of twins! The curtain rises on completely innocent Hane’s new lifestyle as it starts to head for trouble. While he’s taken aback by unique adults, he finds kindness... or perhaps it’s love.