Dino knew, logically, that Mukuro was probably not trying to seduce him just because he thought he was attractive. That was only a minor possibility considering how the man worked.
Mukuro was the very personification of his flame. A roiling mist, concealing everything from view. Ever changing, taking whatever form he needed; be it a charming fox smiling and waiting for the chance to strike, or a silent viper hiding in the grass. A reflective fog where no matter what you were looking at, you could be certain it was not the truth.
Dino knew this. That was why, when Mukuro started lightly flirting and sporadically showing up at Cavallone manor to "chat," Dino was suspicious, at best.
The best case scenario was that he was doing it to provoke Hibari. The two of them had a bizarre relationship that involved two parts fighting, one part fucking, and one part sleeping their respective ways through the Vongola. It could be that Mukuro discovered that Dino had, despite rumor and appearances, never actually had sex with Kyouya, and had come to stake his claim.
And then there was the other option: The one that involved evil plots for world domination and stabbing Dino and taking over his body. But with Tsuna's Hyper Intuition, he could pick out Mukuro after a glance- meaning taking over anyone with connections to the Vongola was risky, if not impossible.
It would never be safe to have Mukuro around, but it wasn't terribly dangerous, either. Just dangerous enough to keep Dino on his toes.
And so Mukuro would show up form time to time, conversing idly or stealing drinks from Dino's glass of wine. Never really doing much more.
"You know," Mukuro had said one evening, "I've allways liked riddles. One in particular comes to mind when we talk like this. It goes like this: You're walking down the road, and you reach a fork. Two men stand at the crossroads, saying that one of them tells only the truth, and the other says nothing but lies. You get one question to figure out which one is which. What do you ask?"
Dino had looked at him carefully. "What does that have to do with being at a crossroad?"
Mukuro rolled his eyes. "I don't remember. You're trying to ask for directions or something- that's not the point."
"Oh. Well, what's the answer?"
Mukuro had only smiled. "Just telling you takes all the fun out of the riddle. You're supposed to figure it out."
"Why do you come to me like this, Mukuro?"
"Hm. Let's just say it's gets lonely in my little glass prison."
Dino frowned. Mukuro had been out of Vindicare for almost a year.
"Hey Squalo? What do you know about Rokudo Mukuro?"
"Little more than jack all. You're the one who hangs out with those brats, how am I expected to know more than you?"
"Because you're actually a Vongola! As a Cavallone, our lines usually only cross socially. I figured maybe you'd worked with him or something."
"The Varia doesn't work for the 10th, remember? We only follow Xanxus, who only follows the 9th." He thought for a moment. "Fran knows him. But I don't really talk to Fran. Why do you want to know about that guy, anyway?"
"He's been hanging around my house a lot. It's kind of unnerving."
"Maybe he's just bored."
"Maybe.... Hey Squalo? Do you know of a riddle where there's two guys, and one of them only tells the truth and the other one only says lies, and you get to ask them one question to find out which is which?"
"No. What the fuck do I care about riddles? They don't apply to real life. Besides, why does it even matter which one is the liar? That's a stupid riddle."
"Yeah... I guess you're right."
"What do you want?"
"I heard a riddle the other day that's been bugging me. There are these two guys standing at a fork in the road, and you're trying to ask directions from them. Um, you can only ask them one question to figure out which way to go, but one of them only tells lies, and the other one only tells the truth. What do you ask to figure out which way to go?"
"You look at a damned map and not rely on idiots."
"...No, that's really not the point of the riddle. The point is that one guy is a liar, and one guy tells the truth, and you only get one question to figure out who's who."
"They're both liars."
"That's not how the riddle goes, Kyouya!"
"Well, how do you know that one is a liar and one tells the truth? Did they tell you this?"
"I don't know. I guess so."
"Then the statement is already false. For them to agree on anything means that either the liar is agreeing with the one telling the truth, meaning he is also telling the truth, or the reverse. Which is impossible. So the riddle negates itself anyway."
"...You are impossible. You know that, right?"
"Yes. It's a stupid riddle anyway. There's no one who only tells the truth- no one. Where did you even hear such a stupid thing?"
"You know he asked you just to fuck with you, right? That's what he does. He fucks with people. He thinks it's funny."
"...Yeah. You're probably right."
"Hey Tsuna- There are two guys; one of them tells only the truth, and the other says nothing but lies. You have one question to figure out who's who- what to you ask?"
Tsuna had looked at him curiously. "That depends, really. Which one are you?"
"That's easy- you ask one of them which one the OTHER would say is the liar. The liar will lie and say that truthful one is lying, and the other one will- wait, I got that wrong. The liar would say that the truthful one would say that the liar is- They would both direct you to the same person! The wrong one! It makes sense, even an idiot like you can understand if you think about it."
"Oh. Thanks, Gokudera. You know... Somehow, I had thought that the answer would be more... Profound."
"It's a damned. Riddle. Riddles aren't profound. Nothing in real life is."
"Yeah... I guess that's true."
He was there again. Chatting idly, lounging around non-threateningly. Flirting casually.
"Mukuro?" Dino asked, tentatively. "That riddle you asked the other day- do you know the answer?"
"Of course I do. Do you want me to tell you?"
"No- I asked Gokudera. Why did you ask me that riddle?"
Mukuro smiled, softly, slyly, secretively. "Because I knew you'd drive yourself crazy thinking about it. Shall we have more wine?"
Dino laughed. Unsettling as his presence could be, Dino still liked having Mukuro around.