Hold really still, maybe they can't see us.
So the maid of honor and I negotiated this shot with the photographer via silent gestures and nod, right behind the bride's back, on-the-spot during the pictures. It was our one goof move, and the MOH has the classic musical theater "stage moment!" look, while I have my maniacal mad-scientist elementary teacher face on. She had no idea until she got the pictures back!