If anyone else has seen Seth Green's full smile from the other stuff he's been in, you'll agree that this makes perfect sense. His smile is ridiculously gorgeous. Oz never smiled like that on the show, and I think it'd be nice if Willow got to see that smile from time to time.
Disclaimer: Willow and Oz are Joss Whedon's, which is why this will probably never be canon.
For most people, happiness is something on the surface. Easy to see. They flash you their toothy grins, laugh, or just have that palpable aura of joy about them. Not him. With him, it's harder to detect. The untrained eye could rarely find what I do when I look at him. They would only see the unwavering mask of stoicism. But I can see the way his eyes light up when he looks at me. The corners of his mouth twitch up just barely, his eyes soften, and I know he's smiling. There were only a few times when the rest of the world got to glimpse how real his joy was.
August sixth, two thousand four. Our wedding day. I almost missed the part where I was supposed to say "I do," because his smile was so beautiful. He smiled a lot that day.
June twenty-first, two thousand seven. The day the twins were born. He held Tara and Daniel for the first time, and I swear the room got about five times brighter with his smile. When he looked back up at me, actual tears of joy were streaking down his face. I'm a dad, Willow. We're parents.
December eighteenth, two thousand thirteen. Tara's first gymnastics competition. She came running into his arms, so excited to show him her silver medal. He picked her up and spun her around until he was laughing and beaming just like her.
April fifth, two thousand twenty. Daniel asked him to teach him how to play the guitar. He looked at me when Daniel passed him the old instrument, and I know he was thinking the same thing I was. That guitar was what had brought us back together. Maybe it would have happened anyway, but it wouldn't have been as powerful without his music. And now he was passing that music on to our son. That wonderful smile dazzled me again.
I know he would give me that smile in an instant if I asked for it, but I won't. I wouldn't cheapen those moments when it comes out naturally by making it commonplace for the world.
Ok, now that you're done reading it, about the kids. Daniel and Tara. Obviously their names were not chosen at random. Their full names are Tara Jennifer Osbourne and Daniel Rupert Osbourne. My deviant art page has a few photomanipulations and drawings of them. Daniel looks just like Oz, except his eyes are the color of Willow's, and his hair is a darker wine-red like Willow's, while Tara has blue eyes and slightly more orange-ish red hair, like Oz, but otherwise looks like Willow. They are inseparable, and have a tendency to finish each other's sentences, which is really unsettling until you get used to it. Oh, and, because of having Oz for a dad, they're both werewolves. In the much cooler, turning into an actual wolf instead of a hideous gorilla beast thing, having of control during transformation, and having of heightened senses as humans, way. Which is how Oz ends up in the season eight fanfic. Also, they've got some inherent magical ability, but haven't fully realized it yet. Yes, I've thought way too much about this.