"Oh." Reading it off of a page from a distant future that might not even happen, and actually hearing Billy confirm it, turned out to be two entirely different feelings. He took a deep breath. Let it out. Took another one. Tried to identify the slightly sick warmth spreading through him and realized that it was was nervousness mixed with pure, unabashed adoration. Something more than adoration, in fact.
"I..." he started, shifting uncomfortably. Billy deserved to hear it. Actually, Teddy was pretty sure that Billy deserved to hear it every day of his life from someone much more capable of expressing affection than he was. But that didn't make it any easier to actually put it out there, even if Billy had already taken the first step, however quietly.
"I love you, Bill, and I'll always go with you if you ask." It came out all in a rush between breaths, sounding more like one of Billy's hurried spells with all the words smashed together than a proper sentence.