Inu wa Kogarete Hizamazuku

"Mr. Warden, the face you make when you're getting fucked... is adorable." He knows he shouldn't enjoy being dominated by a prisoner this much... But in this Dom/Sub universe, the cocksure prison warden can't help falling prey to the dangerous new prisoner...
(Source: Coolmic)
Note: Initially released as 18 chapters, whereafter it was compiled in 6 'episodes'.