This is what they're saying:

"What do you mean? No, I'm not going to do that. I don't care about what you want. I am not going to.. NO! They're my friends now, Frisk! (Frisk.?) I won't- I don't care what they did to you, they wouldn't do it to me! Because I KNOW them!.. I've been actually LIVING with them! No, NO NO! I said I don't care! Get out of my head! Let me be! I will NEVER listen to you, okay?! That was a mistake, letting myself do as you said. I should never have even THOUGHT about killing them! (Do they mean..the genocide?) JUST SHUT UP! GET AWAY FROM ME! (they were screaming and holding their head. I'm surprised no one heard. They pulled a golden locked out of their shirt and broke the chain. They threw it over the balcony and I could hear it splash faintly in the castle's moat. Then they started crying. I felt bad, and almost revealed where I was hiding by the doorway to comfort them.. But Asgore came out. So I stayed put.)

Asgore: Chara? Is something wrong?

Chara: (I'm actually shocked at how fast they wiped their tears and gave him a fake smile) No, I'm fine. 

Asgore: Are you sure? I thought you were crying

Chara: No, just gad a bit of a runny nose.. 

 Asgore: (he hugged them) Alright. Come now, child. I'll take you inside and we will clean you up. 

Chara: Okay, dad. (they took his hand and went in with him)

I don't like this. At all. Something is going on. Something is bad. And not just my attempt at being a secret detective.