Cover embed objects when using a lightbox image. It works by creating an iframe behind the lightbox div, with the same dimensions as that.

fancybox_cover_embeds.js

jQuery(document).ready(function($){
	$('.lightbox-img').fancybox({
		cyclic: true,
		index: 0,
		onStart: function(){
		},
		onComplete: function(){
			var wrap = $('#fancybox-wrap'),
				outer = $('#fancybox-outer'),
				width = outer.width(),
				height = outer.height();
			$('#fancybox-cover-embed').remove();
			wrap.append('<iframe id="fancybox-cover-embed">');
			outer.css('z-index', 100);
			$('#fancybox-cover-embed').css({
				'width': width,
				'height': height,
				'position': 'absolute',
				'top': 20,
				'left': 20,
				'background': '#fff',
				'z-index' : 5,
				'border': 0
			});
		},
		onClosed: function(){
			$('#fancybox-cover-embed').remove();
		}
	});
});