Answer: peeking

AnswerCrossword Clue
PEEKINGKid's game no-no
PEEKINGLooking slyly.
PEEKINGGlancing quickly.
PEEKINGChristmas no-no
peekingPEEK, to sneak a sly look
peekingquick, furtive look
peekingto look quickly or furtively