Sans grinned nervously at the question, sweat visibly beading on his forehead despite the cold. He honestly didn't ever want to start telling everyone, to tell the stars honest truth, he just wanted to keep living in this whole make-believe "everything is okay" mindset and leave everyone else in their ignorant bliss, but that wouldn't stop the threat of his glitched counterpart, nor would it make the fight against him any easier. Mentally he weighed both options, finding both to be just as bad as the other.

Papyrus was probably their best bet for a starting point, but he was training with Undyne and besides that.... Sans just wanted his little bro to have one last day of innocence to it all. Paps was his rock, but he needed one last day of the younger not worrying, just one last night of him being his goofy, happy self. Papyrus deserved at least that much, because tomorrow his training would not longer be subjugating itallian pasta, but learning to evade a real threat and attack them. 

No, Toriel was their best bet. As much as he loathed the thought of her possibly going insane as she had the last time he'd told her, with Frisk there he felt like it might be different. Even then, he wasn't entirely sure how she would react. Would she still look at Frisk the same? Still treat her like the daughter she never had? Or would she shun both her and the entire Underground and recluse on herself?

Frisk's apology instantly wiped away those quickly spiralling thoughts and brought the short skeleton back to himself.

He looked to her with a stretched smile that didn't touch his eyes,"nah, this... this is something we need to do. you know me, i just avoid all the deep stuff and hope for the best. i don't like the conflict." He paused there, thinking his next words through carefully. He didn't want to freak her out, he really didn't, but...,"i think.... i think we should tell tori first. i know you two weren't on the best of terms last time we saw her, but... i think if you're the one to tell her then she'll understand more than hearing it from me."

Sans watched her with a nervous stance, worried that she might vehemently object to the idea. He was being selfish again, and he was sure she could tell, but the thought of ending Pap's joy filled world right now terrified him more than anything he could remember from the past timelines. In the few timelines that he'd actually mustered up the courage to tell him, the older always felt like he was stripping away his brother's innocence and pushing him to change and accept something that was unneccesary, and he didn't want to do that again, at least not this soon.