IsqB:
Let's assume that he LOVES her. Then, remember that before she even arrived at NY, he's seen the Treasures magazine, and she's on the front cover with another guy. He naturally feels insecure about his relationship. Also remember that he hasn't spoken to her since summer.
Me:
Yeah, but that is actually what I'm speaking to. Him giving him the cold shoulder through spring and summer is by itself not something Doumyoji would have normally done. The classic Doumyoji reaction is to raise hell or at least let his peoples know that this was unacceptable, being the jealous guy he is. Acting out is how he resolves his insecurities. And in fact, all of F4 as well as Junpei remark that the magazine would surely draw some kind of reaction from him. But, in this situation, Doumyoji simply does not react. Whatever he feels -- and he probably feels intense jealousy and probably wants to act on it -- he consciously backs away. His reaction actually happens a lot in long distance relationships too. Without her physically there, Makino ceased being real to him. She became a set of memories, a box of cookies, the last time they've spoken on the phone.
IsqB:
Of course he's going to doubt whether M is cheating on him or not. So he might have put a lid on his emotions to keep himself from getting hurt. If that's the case, he told his friends he has no feelings left for M, so that when his friends get back to Japan and M asks, she'll be told that he's not hurt by her infidelity, and they can end their relationship clean.
Me:
Yeah, I think you and I read the interim period completely differently. I think he already decided to break things off with Makino 9 months prior, which is what she herself had suspected. But, by not doing anything about it, not really confronting her, it made things easier for him because he didn't exactly have to tell himself that it was truly over. It's not the bravest thing to do, but for Doumyoji who was changing a lot, it's a very human reaction.
As a result, I come from the assumption that Makino visiting New York only made explicit that their relationship was probably over.
IsqB:
Another possibility (these two are not exclusive of each other) is that his mom interfered, and said basically the same thing she did in the manga. Then he certainly won't want to open his emotions, because I imagine his emotions are already on the verge of spilling, and he's just desperately keeping the lid closed.
Me:
Yeah, I thought about that too, but after rewatching the episode, I suspect that this is an example of the context between the manga and this series. Doumyoji by his own volition break things off with Makino. Maybe he was incredibly troubled by his dream sequences. Maybe it was related to his father (who's supposed to appear on the show.) Maybe in starting to become a human being, his own conscience really tortured him.
He deeply loves Makino; that is always certain, but the sadness with which he looks after her, also suggests that he himself felt that he couldn't save her from himself or his world, or that she couldn't save him from himself. At this point, it is uncertain which one it is.
IsqB:
he's just so wishing she'll understand him without him having to say everything. It's that he CAN"T say anything. So inside, his heart is split between 1) showing his emotions and making up with her and explaining everything to her and 2) push her away and at the same time, protect her.
Me:
Oh, see, I actually think at that point, his heart was shredded, but that he truly felt he had become an adult too. So, there is a bit of condescension there between him and her. He feels he is doing what is best for her, and in that regard, it is very easy for him to choose this path, because he was born to be an authoritarian. As Makino says, it's Doumyoji's habit to do things on his own and leave the rest of his people out whether what he's doing is right or not. It is his nature; only his mother has any power over him.
The puzzling thing is that, for the most part, he decided to act out passive aggressively. And that is truly not like the manga, but very appropriate were Doumyoji acting out in real life. In the manga NY scene, yes he said very indifferent, cruel things in order to protect Makino, but he was never truly passive. He still went out of his way to do the dirty work and hurt her, because Doumyoji again likes to take action.
Here, he doesn't. He has grown up, but he also knows he's running away from her. This goes back to, in this season, Doumyoji essentially making Makino make the hard decisions. Makino is the one who goes to New York to ask what the hell happened. Makino is the one who asks him out. Makino is the one who formally ends their relationship.
It makes complete sense, because that demonstrates how much Doumyoji himself is suffering, and how truly lost he feels. He feels he can do nothing, absolutely nothing for her. For anyone who truly, deeply loves somebody, it is an awful, awful feeling.
IsqB:
Also, you remember what D was mumbling when he "pulled Makino out of the party" only to realize the girl's really Shigeru? He says something along the line of "I wish you'll be more mature, that you'll think things through more, that you don't jump to conclusion so fast, that you can understand things better, that you understand the situation I'm in...."
Me:
But that's the thing. At least in the SARS translation, he doesn't say that. He says:
I'm not gonna make any excuses right now. You're so stupid for falling into that witch's trap. I really have no idea what you were thinking. Anyway you gotta think before you act or else you'll fall straight into that witch's trap. What I mean . . .you gotta grow up a little!
Now, he does give a similar speech in the manga. But the connotation was different there, and it does fit the message you suggest he gives. I would argue that, in this situation, he really is acting exactly how he did in New York, saying the same things, as essentially the "older brother" who yes is protecting Makino, but in no way is implying any "us" in the witch's trap. That is, he's upset that Makino was so "stupid" to get humiliated like that, not because it was an attack on their relationship.
IsqB:
He goes to her after she collapses, but how come he didnt do anything about the red card? Did he trust her own strength or what?
Me:
I just think it's because he hadn't been around Makino for so long, that the red card itself wasn't that "real" to him. By the time Makino had collapsed, they were in each other's live again and she was just around the corner. Meeting Makino face-to-face again had already made holding his own feelings inside really hard, and he had thought about going back on his decision.