Toriel waits, her hand settling on her hip as she watches the younger monster struggle to actually answer. She does not like being lied to, much less by someone who seems to know her relatively well.

The boss monster does pause in some surprise at the revelation. "Oh! Why did you not say so to begin with?" It only makes her wonder why Alphys had lied to her about creating Mettaton. She needed to have a word with that young lady later.

"I'm glad you're back." She means it, Toriel had been waiting for his return just as much as she has been waiting for the other monsters yet to rise.