Oh my god. She just turns up at his house and when he sees her just hanging out like she belongs there Walter pauses like: "...wait a minute." (in this scenario she got let in by his Pokemon and he needs to have Words with them about that).

But ah, she'd be welcome to stay! And all of his Pokemon would be happy to see hers. Darkness will have been wooing Lyra but he'll be delighted to spend the evening with one of his precious Star Pieces <3