They watch him as he confirms what they'd said and then gets up to leave. When he says the sundae's on him, they slide it a little closer to themselves even as he moves away. At the same time, they answer him as he leaves:

"I uzhaj eqh'izh not bad, fi qu me fiaj fiuzh."
"I think you're not bad, talk to me again later."

They aren't really expecting him to answer, but they wanted to say it.