Assuming he does not send you any legitimate hits, block his domain from sending all referrers in your .htaccess
Code:
RewriteCond %{HTTP_REFERER} thisguysucks\.com [NC]
RewriteRule .* - [F,L]
You could be REAL nasty and have another page load in the frame instead
Code:
RewriteCond %{HTTP_REFERER} thisguysucks\.com [NC]
RewriteRule .* http://anothersitethatsucks.com/ [R,L]