He has the Sex Note, use it!

"Why don't you just say no?" Kazuma asked.

"Well, if I did, Lord Alderp would come after you again right away! I had to agree to at least seriously consider the proposal, and... I don't want to let my father down like that... if I don't come up with a valid reason to refuse the proposal..." Darkness trailed off.

"...what if the son himself says no at the end of it?" Kazuma mused. "Yunyun, mind stepping out a moment?" he asked.

"Oh, sure!" Yunyun blinked, walking out of the room.

Now feeling safe that he could talk about the Sex Note freely, Kazuma stated, "I can use the Sex Note to ensure he backs off and allow us to continue our sexual fun..."

"That might work in the short term, but my father would just line up more proposals for me..." Darkness replied.

"..." Kazuma stared at Darkness in a deadpan.

"...what?" she asked.

"You're clearly missing the obvious solution here Darkness," Kazuma replied dryly. "I use the Sex Note on him too for the same effect to make him okay with pursuing relationships on your own..."

"...oh! But what about Alderp?" Darkness asked. "He might cut your reprieve short upon finding out his scheme failed!"

"If he does, we just spread the word that he's breaking his word, seeing as you would have held up your end of the deal," Kazuma replied. "Between his already terrible reputation, and your old man knowing about the deal, even he would know he can't afford to do that," Kazuma replied.

"Actually, why not use the Note on Lord Derp to ensure he leaves you alone so you can keep enjoying your harem?" Megumin pointed out.

"Like hell. I want him to eat crow if possible, getting him to back off with the Note isn't gonna satisfy me," Kazuma huffed. "Making his life miserable is one thing, letting him back off without being publicly proven wrong isn't gonna happen."

"Stubborn, prideful idiot," Cremea face palmed.

"Not really. I totally do intend to do that if the humiliation route is off the table if the month is almost up without me having proof when we reach that point, but I'm gonna see if an opportunity falls into my lap before that last resort," Kazuma shrugged.

"Ah, we should have known," Fio giggled. "Have a backup plan to get out of trouble, but go big before eh?"

"Yep," Kazuma replied.