There are several adult freehosts available... But as a guy who has been making adult sites for over 16 years, i must say that it's a waste of time...
I started out with using freehosts, but nobody wants to do business with somebody using freehosts... It took me two years before i bought my first domain and shared hosting account, made more money in the next month than i did in the previous two years.
When using a freehost it's really hard to get listed on about anything: directory's, tgp's, mgp's, tubes, linklists,... They all want to do business with a guy using his own domain and a reliable host...

That being said, PM me if you need some help with your plan, i'm pretty sure i can point you in the right direction.