To ensure that doesn’t happen, swipe up on the face to display Control Center, and then tap the theater masks icon to enable Theater mode (you may have to scroll down to see it). That automatically turns on Silent mode and prevents the screen from lighting up unless you tap it, press a button, or on the Apple Watch Series 2 or 3, turn the Digital Crown. To leave Theater mode after the performance, tap the masks icon in Control Center again. Enjoy!
