Discrimination Sex -If you choose the wrong partner, you'll be cuckolded-

In a certain country, there was a prince possessing a special sperm known as the "seed of God."
Any woman impregnated by this divine sperm could give birth to a child with overwhelming magical power.
…This special sperm caught the eye of the succubus king, and one day the prince was abducted to the land of the succubi.
If the prince's sperm were to be scattered among the succubi,
many succubi with immense power would be born, and humanity would be dominated by them.
The prince vowed to protect his beloved people, vowing never to ejaculate.
To mock the prince, and to select a succubus worthy of bearing a special child, the succubus king declared the holding of a competition.
The name of the competition was the Wedding Battle Fair.
The nine succubus princesses who ruled the succubus kingdom were chosen as participants.
The prize: the right to become engaged to the prince.
The rules of the battle were a battle-fuck contest where the prince and the demon princess would make each other orgasm.
The demon princess's victory condition was to become pregnant with the prince's child right there in the ring.

This game is set in a fantasy world where you are trapped in a room where you can't escape unless you have sex with an elf, a nun, or a beast girl.
You can also enjoy sex with tentacle monsters and the classic goblin.
The game emphasizes gentlemanly elements over gameplay.