Peter nodded, yeah that was the way to do it - just talk at them like they knew what the humans were saying and maybe it'd all work out. Peter had done it too of course so he was absolutely not bashing the idea. He watched as Carol spoke to it, asking the little guy if he wanted to come back with them and then it actually made a noise that could be agreement. "Okay, that is adorable."
And as they started walking he glanced back to see the little guy following them, amazing, truly. "You found him just like this?" Peter asked doubtfully. He was sure that wasn't exactly what she meant but he could tease a little bit too.
"So I guess our next move should be getting you one of the pokeballs and then we can see where we go from there." Peter suggested, if the little guy was ready to come back with them Peter had a feeling he wouldn't mind the balls either, and it'd make it easier for Carol in the long run to have one too.