For the most part as soon as she had approached him Sephiroth didn't understand what the urgency was so he blinked. That was before he'd heard the rest of what she had appeared gleeful about. If he could call that. But as he was presented with said photos with their children, a smile would come about upon his face. His face began to hurt and he began to chuckle just thinking about it because he must've looked a sight just now. And he just so happened to have caught himself with a bit of a toothy one. This doesn't really happen with him. Hardly ever if one wanted to be blunt about it. Scooting close next to her once he patted the area on the couch next to him, he'd glance over the photos more closely. He wanted to join in with her gushing about their children. Even when he wasn't particularly someone who was set in his ways with fatherhood. It was still pretty new to him at times.
Who would've ever have thunk someone like him as fatherly material? He had definitely never thought he'd ever have come the day he'd see it happen. After a moment he'd fish out his phone and snap all of the photos only to make his own copies of them and then uploaded them. At least there'd be extras if one or both of them had happened to have lost the originals. One hand over his face half way and he'd still laugh again. This was more like an awe thing then it was ever about amusement. Well, a little of both. It was just like it happened yesterday when they were first born. Sure, there would come times he'd have to yell at them and they'd drive him insane, but that wouldn't mean he'd love them any less. He'd only yell at them for 'Dad reasons'. He knew there would come moments when he cross beyond that line, and when he realized it happening and when it suited the moment within reasoning, he'd apologize and make amends.
That's when the stubbornness would subside and be over with.