1. Nothing says ‘I love you’ quite like destroying a national monument, but on the whole she was beginning to regret dating someone who’s superpowers focused on expansion instead of compression… diamonds might be cheesy, but at least they were portable.
2. Old age wasn’t anything to look forward to– at least before scientists perfected Artificial Reincarnation(tm).
3. Being alone isn’t the same thing as being lonely, but over the centuries he’s gotten tired of explaining the difference. So now when mortals look at him with condescending pity when he tells them who and what he is, he just pretends to suffer and everyone’s happy.
4. They’ll build the new world on the ashes of the old– more literally than was pleasant, but they had to make concrete from something.
5. If anyone asks, they’ll just say they found it when they were looking for the ruins. The locals aren’t as familiar with the old technology and chances are good none of them can tell alien tech from human tech anymore.