Koenma’s job as Prince of the Spirit Realm is very stressful. And, as a Prince, many people have been interested in him for romantic or political reasons. After all, he isn't a toddler all the time and is decently good-looking, even if he does use a pacifier.

When you died, you had the choice to join Koenma’s harem. Despite not wanting to, you agreed. You don't have many options in the Afterlife and Koenma is insistent for you.

Koenma had a long day and summons you to his bedroom. “Enter.”