All things considered, Kagetora is remarkably not a cocktease. Now, I will tack on the disclaimer that I have not had access to all of the canon, and it would be very easy for me to miss something, therefore. But from everything I HAVE seen, there is nowhere (before book 20, anyway) the slightest hint of Kagetora deliberately attempting to be seductive. Nowhere! Nor is there anything to suggest that he behaved otherwise before his Takaya possession. The man is fundamentally uncomfortable with sex, and understandably so. He endured a horrific gang rape at a young age. Apparently he didn’t even like having sex with his first wife. He did, to fulfill his duty of begetting an heir, but he felt “dirty.” After that, the only other hint we have that he may have had an intimate relationship with someone is Minako. And we’re never told whether he actually slept with her. One might wonder, for instance, how he immediately knew that Minako’s child was not his? Personally, I am inclined to think that he did sleep with her, if only because there are some mentions made of him reclining on her “motherly” bosom, a description which kind of made me go o.O Okay, so Minako was motherly to him, and he views Naoe as a father figure (at least at first)? Yeesh.  But I digress.

Yes, he might have slept with Minako, but that was obviously a serious relationship. In the Takaya possession, he never dated or had a girlfriend, though according to Saori “lots” of girls probably liked him. In the manga based on 5.5, we see girls hitting on him and his disinterested dismissal. Mitsui notes that Takaya seems uncomfortable with sex, and makes fun of him for it. Mitsui hits on him (very creepily), and Takaya responds by slamming him in the gut so hard he flies across the room. When Naoe reveals to Takaya that he has a penchant for one-night stands, he notices that Takaya seems weirded out by the thought, and chalks it up to “a prudish streak” or just immaturity.

My point in all this should be clear, as I’ve repeated it half a dozen times: Kagetora is very uncomfortable with sex. He does not behave in a sexual manner except within the context of a serious relationship (so far as we know, and I think that’s a reasonable assumption), and those are few and far between.

 The one who uses sex as a weapon in their relationship is Naoe. Whenever he wants to get a rise out of Kagetora, Naoe either molests him or says something sexual to him (or both). Why? Because he knows it bothers him. Sex is about the only area where Naoe has the upper hand, and he knows it, though he doesn't know why. 

Kagetora never says or does anything to Naoe that could be construed as sexual in nature unless he is forced,  protesting what is happening, or referring to their win/lose thing (and only then in a very vague way). The closest Kagetora ever comes to voluntarily bringing up the subject with Naoe is when he uses what Naoe said earlier to try and keep him interested in their win/lose thing: “If you beat me, then you can hold me.” That bet is referred to multiple times, later.

The impression I got from that whole thing was that this was something new, a gauntlet that Kagetora had tossed down in sheer desperation to keep Naoe from giving up and leaving. It seems, from other places in the novels, that both Kagetora and Naoe think that Kagetora going to bed with Naoe would signal that he had lost/surrendered. So, really, it isn’t as though Kagetora is saying anything new, so much as rephrasing it to slap Naoe in the face with some of his own dirty talk (with the really bad bits cut out).  So I interpret it as more like he’s saying “You haven’t beaten me yet, bastard. You’ll just have to keep trying.” Oh, and he does say one other “sexual”  thing- during a fight, he makes the comment, “sleeping around doesn’t make it any better, does it?” Which is pretty nasty, but not exactly a come-on.  And again, nowhere near the direct dirty talk that Naoe uses to freak Kagetora out.

Otherwise, he barely even acknowledges that Naoe wants him that way- he tends to think of Naoe’s feelings towards him  (and everyone else’s) in a non-sexual light, even when it’s reached the point where you’re wondering how dense he can possibly be. Example: Naoe’s first come-on to Takaya. In the novels, he forcibly kisses him. Takaya’s reaction: why does he hate me? What did he want to do to me? Um….Takaya, dude. What do you think he wanted to do to you?!  “Immature” or not, you’re a high schooler in a country where kids your age and younger are highly sexualized. And, y’know, he kissed you. Shouldn’t that be a dead giveaway?

But the thought that someone would be attracted to him does not easily enter Kagetora’s mind. Sure, he notices that people are hitting on him (sometimes) but it seems like he usually thinks that they’re just trying to dominate him, not actually finding him attractive (the fact that the desire to dominate him usually DOES combine with attraction toward him aggravates the problem). Kagetora does not view himself as a desirable person. And when people come on to him, it isn't because he does anything in particular to attract or encourage their interest, and he frequently is not aware that they even have any.  It's just that Kagetora has some kind of animal magnetism, an immense sex appeal that he has no control over and seems to be completely unaware of.

Consider: when Kaizaki-Naoe has him handcuffed naked and drugged to a bed, and takes the opportunity to molest him quite thoroughly, Kagetora's first theory as to why this occurs is pity. He thinks it was a pity fuck! Dude. What makes it really ridiculous is that this took place after that other guy had come in and tried to molest him immediately prior to Kaizaki's entrance. And then Kaizaki had started flirting with him right off the bat, before Kagetora became upset. Good grief, he still thinks it's pity even when Kaizaki comes and meets him much later on and gropes him. How clueless can you be?

Kagetora: I don’t want your damn pity!
Kaizaki: Oh, come on. You can't honestly think that’s all it is.
Kagetora (thinking FURIOUSLY): ? Well, come to think of it, he was pretty rough with me, which wouldn't make much sense if he was just trying to be comforting.
Kagetora:...
Kagetora: (surprised): He wanted me. Right?

Give the man a prize.

Kagetora doesn’t really think that Naoe finds him desirable, either. He thinks that Naoe just wants to "conquer" him, that it's all some domination game to him. And when it's over, Naoe will just get bored and wander off. Which is why he refuses to give in to Naoe in the first place. Putting sexual intimacy issues and personal dislike of being used/subjugated aside, Kagetora won't allow himself to give in to his feelings toward Naoe because he thinks the minute he does, Naoe will be off to the races. Even if Naoe actually does love and want him, the real him, which Kagetora HIGHLY doubts, he considers any love which he might inspire to be insufficient to have kept the man by his side all this time. Really, it must all be about Naoe's ego. Naoe wants to win. When he does, the game will be over and he will leave. Kagetora can't stand the thought of losing Naoe, so he plays along. He may have other reasons for doing so, as well, but his primary motivation is keeping Naoe with him.

Conclusion: Kagetora does not cocktease. There is no real evidence of him doing so, and it is highly unlikely given what we know of his character and past that he would. Kagetora is extremely uncomfortable with sex. He doesn’t think of himself as desirable, either, which would mean that it probably wouldn’t occur to him to use his sex appeal to his advantage. Within the context of the Naoe/Kagetora dynamic, it is primarily Naoe who uses sexuality as a weapon.