"Oh. I guess I have not done as good a job as I would have liked of hiding how much you frighten me."

The words keep spilling out. She really wants to just... leave. To just turn right around and sprint away before things get worse. But... there's a lot of truths here. Things she hasn't talked about, that she not only has to be honest about, but is compelled to be honest about, and that compulsion is rooting her to the spot.

She's going to wreck her relationship and hurt this young child and there isn't anything that she can do about it. Toriel just looks... frustrated, and resigned, as she realizes it. It's like she's a passive observer to the scene, as her voice works without any real input from her.

"Because you do scare me, a great deal. Every time I think of you, I remember it, no matter how hard I try not to. How much vicious, killing intent you put into that single blow."

"I am truly sorry that I feel that way," she manages to get out, wresting control from her compulsions to add at least some kind of comfort to it, something that really is true.