You could cut out two of the lines by going to:
Code:
RewriteCond %{HTTP_REFERER} ^http(s)?://([^@\/]+@)?([a-z0-9-]+\.)*coolsexvision.com(:80)*(/.*)* [NC,OR]
...and the same for the other domain you want to block. That will take care of all possible variations on the domain names and also upper and lower case variations.
Only [NC] at the end of the second/last domain line of course.