Theodore didn't know how things had suddenly gotten clearer in his head, or how long the clarity would last. What had caused it, though, was the realization that Pansy always had, and always would, be the first thing he factored into his choices. The only way to prevent that was for her to be out of the equation entirely, and that was no longer possible. No matter how much he'd cared about Blaise, if he tried to cling to that, he would always hurt Blaise by going to Pansy's side when she needed him, and he would never be able to pretend that it was just because she was just his friend.
He'd hurt Blaise, albeit unknowingly at the time, and he would always feel guilty for that. But he could let Blaise heal and hopefully find some kind of happiness, whether it was with one someone or multiple, without constantly having to deal with Theodore's enormous double standard. And Theodore couldn't have regressed to what they were before, either. He had an ideal for a loyal, monogamous relationship, and it was an ideal that, he now knew, was based on what he and Pansy could have.
How long that had been true, he didn't have the faintest idea, but he and Pansy were... well. They were imperfect, but they endured. They got past everything, together. It was the best, and probably only, way to fix things completely, to reduce as much pain for them all as possible.
He still remembered the way Blaise had taken him by surprise, the way he'd kissed him back and wanted him, the way just looking at Blaise had an effect on his heart. That wasn't going away, and he wasn't going to pretend to himself or to Pansy that it would. He couldn't lie to Blaise about it, either, but he could make it easier, maybe; he could find a way. Somehow.
But he did need Pansy by his side. She made him stronger, was his voice of reason when he couldn't be his own. It was pointless to debate about whether it was the perfect time to be hers, when he knew deep down that he already was. Now that he'd realized that, he was here, standing outside her door, hesitating only a moment before giving the password.
When the door opened, he stepped in, smiling genuinely when he saw her, even if the look in his eyes was still a little bit troubled. But he wasn't trying to pretend to be perfectly happy, she'd see right through it anyway.
"Hi," he said, and then, taking a deep breath, "I love you, Pans."