Sans finds it especially concerning, as well. He ducks his head again and nods his apologetic confirmation of the question. He hadn't wanted either of them to know, which was why he'd first hidden the lab while Frisk had been dead and then both moved and abandoned it once they'd returned. Then again, S-4 had found it anyway, once or twice. He supposed it wasn't infeasible that Sans-Serif had been poking around as well.

Then again, the kid had also been getting very perceptive, as of late, about things he had no business being perceptive about...but that was a worry to be understood in another time.

"Sorry," he says again. Carefully, he starts to lay himself back down on the grass.