I'm sorry for the lame title T____T I couldn't think of anything better, (Titles, the bane of my writer-ness)

I swear to you this is true, it came from OMG facts.

^___^ Please enjoy

Disclaimer: I do not own Tsubasa or the science of sex

Warnings: Inferred & implied Sex, Kurofai, Yaoi

Kurogane wasn't in the mood for sex. Why? He just wasn't, tired, he thought. So when Fai started to walk up to Kurogane, (Gee, I wonder what he wants… Kurogane thought sarcastically.), he had to find an excuse to make Fai leave him alone (for once)

"Kuro-sama~" Fai whispered when he was standing in front of Kurogane. He wrapped his arms around Kurogane's neck and reached in for a kiss, which Kurogane accepted happily, but he had to think of something.

"You know what I want~" Fai whispered into Kurogane's ear after he broke the kiss,

"Fai- Oh, don't do that!" Kurogane chastised Fai when he bit his ear. "Fai, I don't want to have sex tonight-" Fai cut Kurogane off with a loud gasp,

"What? Why not?" Fai whined, giving Kurogane the cutest pair of puppy dog eyes he could manage.

"W-well," Kurogane started, trying to resist the eyes, "I..have a headache…" Fai straightened up and looked Kurogane straight in his eyes, giving him the most serious look he had ever seen on him,

"Now, Kuro-sama…I am certain that is a lie. A big huge, fat lie." Fai sighed and his forehead creased, "Let me educate you on something." Fai cleared his throat, prepping what he was going to say,

Kurogane just looked at Fai, slightly scared at what he was going to say because, with Fai, it could be anything, anything at all.

"Having sex can reduce a fever because of the sweat produced. Sex is also a pain reliever, ten times more effective than any pain reliever: immediately before orgasm, levels of the hormone oxytocin rise by five times, determining a huge release of endorphins. These chemicals calm pain, from a minor headache to arthritis or migraines, and with no secondary effects. Migraines also disappear because the pressure in the brain's blood vessels is lowered while we have sex." Kurogane stared at Fai, dumbstruck.

"Oh…" Was all Kurogane could manage, "Wait, how the hell do you know that?" Kurogane asked, looking funnily at Fai, who just smiled at him,

"In Celes, magicians were also doctors, so we had to know that. And….I have…traveled to other worlds to learn more about things like that." Fai looked away at the mention of his home world, but quickly turned back to Kurogane with a smile,

"So, in essence, having sex would make your "headache" go away and make you feel better."

"I see…well, I can't beat that logic…"

"Nope, you just can't," Fai smiled at Kurogane, who looked at him with a sly smile,

"Well, what are you waiting for?" Kurogane asked, taking Fai's hands. Fai looked at him confused,

"Uhm…what do you mean?" Fai asked, looking at the odd smile on Kuroganes face and their interlaced hands,

"You made my "headache" go away with your explanation. So, let's go," Fai smiled in realization and allowed Kurogane to lead him away to his room.

Syaoran swore he could hear moaning and groaning all night, but he wasn't sure who it was. Well, he wasn't sure until he heard,

"Oh, Kuro-rin~!" from the room the moaning was coming from.

After that, he knew exactly who it was.

And, he took the princess and Mokona out to a movie so they wouldn't hear/figure out who it was.

So? What do you think?

This was too good not to do!

I should done it Horitsuba-verse...Fai is a science teacher and would know this, but....I was already done when i thought of it.

Maybe I will, depends on what you, (the reviewer(s) say,)