DreamHost allows adult content just as any other content - as long as it's legal. Here is their statement about this:
Also check out their terms of service.
you can't have a URL that's like http://www.dreamhost.com/your_stuff_here/, but you can have http://your_stuff_here.dreamhost.com if you like. You can of course also simply use your own domain name. Even in their smallest plan (which ISN'T small!) you get a free domain name registration and free domain renewal forever, so there's not much reason NOT to have your own domain name!
Try out DreamHost with a free WebID -- Prices, options