This Cheapskate Knight Wants to Make Me Cry

Lute is the son of a tavern owner in a castle town, and he has a secret... when he sheds emotional tears they turn into magic stones, or "gems." One day, the royal knight Advald, a regular patron notorious for being a cheapskate, sees Lute crying outside the tavern and discovers his secret. Now, Advald wants Lute to cry for him to get more gems... by having his way with him between the sheets!! Source: Renta!