Eli was late, mostly because he had had to perform a bit of a covet operation to get out of his house. And by the time he arrived he realized he was being referenced, so he made a point of standing outside the door and listening and Superman spoke. It was... More than a little awkward.
When he got to the par about the suspected camps, Eli poked his head in and wanted to yell, "That's exactly what I have been talking about!", but this was Superman. So instead he managed to keep his mouth shut, and listen to the rest. It was no better, and the tests sounded exactly like what had happened to his grandfather. Except these ones were voluntary, at least for the moment.
Once attention was shifted to Kate, he ducked back out, as he did not particularly care to stick around and talk about what had happened at school with the team, let alone Superman.