ScarabWeb does allow adult websites as long as they do not contain illegal material.
This can be reviewed in acceptable use policy which can be viewed view at the following link:
http://www.scarabweb.com/policies/aup.php
As long as your site complies with federal laws, then it should not be an issue. We would however recommend dedicated hosting for such a venture as sites of this mature become very popular very fast and could potentially cause an issue on the shared hosting environment.
