She thought she’d turned the watch off. She’d been unerringly careful until now, making sure it was always one watch, never two, that beeped just loud enough to disrupt the motions of the day.
Of course, Scotty hadn’t expected to see him today, hadn’t had time to remember something as painfully normal as the settings on a watch. (which lends a sort of awful juxtaposition on the condition it monitors-- spider infestation held in check by a simple watch. it seems sort of indescribably delicate in face of the world(s) they live in)
The mistake is inevitable, really, but that doesn’t make her scramble to turn the thing off any less urgently embarrassed-- a second later Scotty pretends she’s noticed something in the grass several feet off and heads that way without looking at Charlie (either one) or anyone else (she can hear Peter trying to hide a laugh. it’s a bad job.). It’s more an effort to buy time than because she thinks that will really fool anyone.