Steve had literally no clue that he was about to meet his own son. Even having met the young Coulson boy, the thought that he might have a child of his own was completely foreign. If he noticed Andrew's nerves, he chalked them up to the sudden change in circumstances. Strange day, strange new universe. Understandable, right?
"I think that's him," he murmured to Jean, and then called out a warm greeting.
"Hey. I'm Steve. I think we talked on that Internet network thing?"
That's right. Network. Thing. Apparently he was still catching up on tech.