[Sayato] Bluff Relationship (COMIC Masyo 2023-07)

A well-endowed teenage cousin uses a new water gun toy as her excuse to share a bath with her younger relative, setting off a secret affair neither can resist. What starts as playful splashing quickly escalates into eager fingering and squirting, followed by a sloppy handjob and blowjob behind a parent's back, before she rides him to an ahegao-faced, cumming-until-he-finishes-inside climax. A teasing bonus page hints the awkwardness is only just beginning.