What are the search terms that will lead me to stories where someone grants a boon or petition, and the person requests something ridiculous, and the person granting the boon has to do it because he'd lose honor if he refused? I seem to remember a king granting boons to celebrate his wedding, and someone wanted to be the first to sleep with his wife. I can't seem to find any information except that the word boon could be used in that way.
I remember hearing the term boon before. Meditation Masters go through mental trials (psychological torture) to receive super powers from a Devi or Asura. These creatures could lose honor if they refused to give power to someone who "passed" their trials.
In general, boons are favours or gifts not as binding as an oath or debt of honour. Asking something unreasonable is more likely to get the person killed than in bed with the king's bride.
Western civilizations didn't have such a strong sense of honour that would get a King to concede his bride. But the other way around worked, most Kings and other nobles had the so called ius prime noctis (right of the first night), meaning that they could consume the first night with any new bride in their county or land, or whatever the claim was.