The spellbound wizard

Theo was taken in by the wizard Klaus when he was a child.
Even though Theo is Klaus's disciple, he grew feelings for his mentor but spends his days taking care of him without daring to confess.
One day, Klaus hears that the price for obtaining a precious magical material is spending one night with the king of a foreign country…
"If you can give yourself over that easily then give yourself to me-!"
Can the out of control Theo really spellbind Klaus?