There's a flash of relief as the slip doesn't result in any sort of backlash, or upset, eyes catching Tommy's to make sure they're okay, and he dares for a small smile. Brothers. Whether the test proves it or not, that's what they are. He's sure.

He starts to nod at his mother's suggestion, and then pauses uncertainly. "...Will it be weird for him...to be here?" he asks, looking for reassurance. There's no sign of what had taken place, but this is still the scene of his mother's death.