I need this for AD banner i whant to try to make some click on fast way and than to buy some traffic to make CTR normalAre you trying to hide the ads but still get impressions? This will violate most advertising companies policies, but it's still possible.
When you say 'invisible' what type of ad are you talking about? A banner ad or a link?
As for behind the image of a play button, this is possible with javascript having a temporary ad appear and when the user clicks it then it disappears. I'd need to know more about your code in order to help though.