[Body language was never Sans' subject of choice to study, but it was without question the area he got the most opportunity to read. The smallest ticks and twinges could spell entire stories. The angle of a furrow on a small child's brow could be the difference between knowing they'd seen death twice or thrice.

Expressions told all sorts of stories. It's one of the many reasons Sans decided to swear most of his off. Still, some faces were easier to read than others.

The way she curled in on herself, the dark cast to her energy, the dimness of her soul -- it could mean so many different things. In this case, though, Sans decided don't touch me might top the list. Followed closely by I feel unsafe.

Not much he could do for the latter, but Sans kept his hands folded over his lap and his eye sockets back to the ground.]

Well, your dad made a choice. [And that's exactly how Sans sees it, too. Her father decided to do something -- something Sans can't even bring himself to think in much detail, such was the extent it horrified him. J's agency in the situation may as well have been that of a prop.] And then your mom made one.

As far as I see it, the only one who didn't have a choice was you.