Purple's not unfamiliar. Sans saw that spider girl in Hotland do something similar. He had stood still, frozen at the magic flaring, the shadows growing. He wasn't sure why -- surprise and confusion probably -- but now he was cursing himself as he tried to jerk away and realized he couldn't move.

Some random thought in the back of his mind wonders if this is how the kid felt.

Doubly cursing his additional weight, he tries to twist his body to the side, as if makes himself any less uncomfortably close to Gaster.

What the hell.

"Da.... doc, what... come on. I don't know what you're talking about, but knock it off."