Robin's been affected, but pucks have a tendency to keep their angst to themselves, so he'll be in the kitchen when Titus gets there, making coffee, because cafeine where you're nervous is apparently the way to go. This incoherence alone is telling of Robin's discomfort, but it's not something a stranger would pick out, very likely.

When he spots the young man, he blinks at him, tilts his head. "--- whoa, you look like you're having a rough night, buddy. Nightmares?"