He honestly had no intention of making Steven upset? Although yeah, he's... probably backing off a little bit more now, because he clearly looks upset.

And he's also... not entirely surprised when Steven finally says that he was taken away. It's something that his own parents had heavily implied when he'd reported back that day that Steven had just gone missing and Greg had refused to say anything about it beyond the bare minimum.

To be fair, his parents hadn't quite hit on the supernatural or fae aspects of it.

His expression is a little bit more grim when Steven doesn't say anything further, but that's more because he's trying not to get too worked up or agitated - he still can't quite make it stop sounding like a growl when that happens, and the last thing he wants to do is to scare Steven even more because that would... probably not end well at all.

"... How long have you been here?" He's going to take a stab in the dark and assume that Steven hasn't gone home at all, mostly because if he had, Matt would have seen him, and Greg would... probably have said something? Greg looked terrible the last time Matt had seen him, anyway.