sneak a peek
sneak a glance
sneak a look

She could not keep from sneaking a glance toward his feet.

She sneaked a glance at the thing that was Bill.

Junior had sat playing by himself and sneaking glances at the door.

I went back, sneaked a glance around the edge of the open door, saw a man at a desk, talking into the phone.

She sneaked a glance at him, but he was gazing up and down the street.

A few seconds later Jack sneaked a quick glance to his right.

Some of the prettiest girls in the class began to sneak glances at me.

He sneaked a glance across to Webster to see how this was being received.

Squares stopped for a red light and sneaked a glance at me.

More likely, these two were merely curious, sneaking glances at me.