Koisuru Milk Crown @ Zetsurin

Sakisaka Reon, who works at a boys' bar, is in a steady relationship with cafe owner Hodaka Shuusuke. Reon is pampered by his older boyfriend, who brings out sides of him he never knew, leaving him feeling a mix of flustered and comfortable. Meanwhile, their unusual sex continues to escalate day by day...
(Source: Ichijinsha, translated)