[Mettaton can't exactly stop Asriel from feeling guilty this time...which in turn makes him feel guilty for inciting those feelings. However, he doesn't bring it up. It's much easier to focus on what the young boss monster had been up to lately.]

It's probably for the best that you didn't. There's a chance of something dangerous being in there. Even the bravest person shouldn't go alone.

[What if Asriel had ended up lost? Or hurt?? Ugh, Mettaton didn't even want to think about such a thing.]