Loading post comments after clicking a button

You could try an easy jQuery approach of hiding the comments div and inserting a button to make it appear.

Instructions:

In your functions.php file of your theme, place this line of code to ensure that jQuery has been included to run the code:

wp_enqueue_script('jquery');

Then you could add this function to place the javascript code into the footer of each of your webpages:

function your_hidden_comments(){ ?>
<script type="text/javascript" defer="defer">
var comment_div = jQuery('#comments');
if(comment_div[0]){

    jQuery('<button id="show_comments">Show Comments</button>').insertBefore(comment_div);

    comment_div.hide();

    jQuery('#show_comments').on('click',function(){ comment_div.fadeIn('slow'); jQuery('#show_comments').fadeOut('slow'); });
}
</script>
<?php } 

add_action('wp_footer', 'your_hidden_comments');

I hope that helps; comment back if there is any trouble with this.