We already had quite a lengthy walk on the way back here. [ Not that the energetic little dog seems any less tired for it. ]

You are right though, I've quite a lot to get for him. [ A possible alternative then occurs to him - he honestly looks so genuinely pleased at the prospect, as though he couldn't possibly think of a more wonderful idea...: ]

Perhaps he could stay here with you so the two of you can get to know each other? I shan't be gone long.