He really should be used to being randomly yelled out. Then again they usually yelled out his name or some variation of 'that's Flynn's kid" while doing it. So moving in a bit of a circle in confusion to locate the one who had yelled out.

Welp Kay, he's also a bit surprised at seeing a you as well, and you actually trying to catch his attention there.

"Hey yourself. Did I snag something you were looking at? Though I didn't think many would be interested in junk that much."