Aether couldn't take it anymore. Tossing up his hands, he fell face-first on the textbook's open page. Why did he agree to this? Sure, Paimon, I can study up on some economics so you can get rich like Ningguang. No problem! If only he knew how to say no.

None of this crap made any sense. All its "rules" seemed so arbitrary and riddled with exceptions. He sighed, disappointed. He always thought of himself as at least slightly above average intelligence. This economics thing made him feel like an absolute moron.

Someone knocked.

"Come in," he said.

The door creaked open as a set of heels clicked across the floorboards. An ever-elegant Ningguang strode into the room. "Pardon, I heard you sounding rather upset. Is something the matter?"

He smiled softly. "I'm trying to learn this economics stuff for Paimon, but none of it makes sense."

Ningguang pulled up a chair and sat down beside him. "Well, perhaps I can help."

"No offense, but I don't see how even you could make this remotely intelligible."

"I have my ways," she said. "What's bothering you?"

"Well, there's this bit on positive externality that I don't get."

"A positive externality is when someone makes something else that you benefit from without paying for," she explained. "For example, Rex Lapis built much of Liyue. That includes the public parks. If the two of went for a stroll we would enjoy those parks for free. Your presence for me is one big positive externality."

"Thanks, that's nice of you to say. I think?"

Ningguang cleared her throat. "Now the problem with public goods like a park is that such goods lead to a free-rider problem. If most people don't have to pay for a good to enjoy it, then that good could be underfunded and business won't have an incentive to provide the good."

Ningguang smiled. "Are you a public good, Aether? I could free-ride you anytime."

She chuckled at her little joke. Aether laughed along, even though he didn't understand why Ningguang would want a piggyback ride. The uber-rich had weird hobbies. And maybe it was his imagination but she seemed irritated. Probably annoyed at how slow he was getting the subject.

"Now a private good in contrast," she said, "is a good owned by a few people. Its excludable nature means a few people can own it. This could be ice cream or sweet madame. What do you think, Aether? Would you like to be my private good?"

"Ningguang, are you saying," he paused, "that you want to eat me?"

She gave him a blank stare.

"Because I'm like ice cream?"

"A private good doesn't have to be food," she said dryly. "It's just, something that only one person can own at a time."

"Oh, okay. I'm also struggling with…" he flipped to the earlier chapter. "Law of demand and supply."

"Ah yes, those are crucial economic terms. See this graph, how the line slopes downward? This is the law of demand in action. The y-axis is price, and the x-axis is quantity demanded. Notice, that as the quantity demanded gets higher, the price gets lower. Why do you think that is? Why would a person pay less the more of something they want?"

"I think the book said it was because of diminishing marginal utility."

"Very good. Indeed, the benefit anyone gains from something typically decreases the more of that something they buy. Of course for you," she said, "my demand curve slopes upward."

"But…demand curves slope downwards, not upwards. Are you saying there are some cases where they slope upwards? Man, I thought I was getting this thing."

"No, no," she said hastily, "I was just…making a joke."

"Oh. Well, maybe once I get this economics thing, I'll understand the joke."

"We can only hope," she muttered under her breath. "Now the law of supply works like this: the higher the price someone is willing to buy something the more of that something the seller will produce. Hence the supply curve slopes upwards. Where supply and demand curves intercept, supply and demand are at balance; which we call equilibrium."

"Okay, and can you explain this graph?"

She leaned over to get a better look at the textbook. In doing so, her breasts pressed into his forearm. He blushed, feeling the squishy mounds. Gods, they were nice. Right now, his crotch was looking quite a bit like this demand curve. Focus, he chided himself. But all he could think about were how nice her chest felt against his arm. Ugh, he had to get out before she noticed.

When Ningguang finished an explanation he hadn't been listening to, Aether nodded. "I think I understand now. I'm uh…going to take a little break."

He crossed the room in an instant.

"Aether, wait," she said as he opened the door. "Do you want to make love?"

He stopped dead in his tracks. "Wh-what?"

"I figured I might as well come out and say it, since you're not getting it."

"Not getting… wait a second, are you…flirting with me?"

"I have been for the last five minutes, but thanks for noticing."

"You have? When?"

"Morax preserve me…I said I could free-ride you anytime! What do you think that means?!"

"I don't speak economics."

"Right. Enough subtlety. Aether, kindly lead me to your bedroom. I want to ride you, and not like a horse. Get it now?"

"Yes, ma'am."

Ningguang stroked her lover's bare chest. Aether was regrettably dense, but his performance more than made up for his shortcomings. A body this wonderful and a heart so gentle were rarities indeed.

He stirred, looking at her with a smile. "That was fun."

His fingers combed through her long platinum hair. With the other hand, he traced circles down her pale back, making her shiver. Yes, she decided, this had been a wise use of time.

"I'm only sorry I couldn't help you with your economics," she said.

Silence hung between them. A long stretch of silence, in which Ningguang worried she'd misspoken. At last, he shifted to a sitting up position and tenderly guided her into his lap.

"Hey, Ningguang," he said. "I'm the supply, you're the demand. Together, we can be at equilibrium."

She rolled her eyes.

"No? Then how about this: girl, let me supply your demand, cause I love the way you shift those curves."

Okay, she had to give him points for that one. Surrendering a little snicker which he took as encouragement.

"Baby, your booty is one big moral hazard. Let's go to bed and disprove the law of diminishing marginal utility."

She bit her lip, playfully giving him a light slap across the shoulder. Truthfully, this economic talk got her kind of excited. It proved he tried to understand her.

"Okay, okay, one last one." He cupped her chin. "We're like unemployment and inflation. You know why?"

She shrugged.

"Because, the more you go down on me, the more I grow."

That did it. Ningguang pushed him onto his back and grabbed his ankles, forcing his crotch up in the air. Ningguang licked her lips, hungrily, as she forced him into the amazon position. Aether swallowed nervously.

She growled ferally, "I'm going to drain your balls, my little economic lover."

Ningguang proceeded to jackhammer the traveler well into the night. Now, Aether understood what it meant to be a public good getting loads of free-riders. In this case though, he kind of liked it.