since it is an adult domain you are looking for, posting a budget limit of what you would pay on the adult forums is a good way to get domains offered to you
check sedo.com and do a search for your keyword
check tdnam.com and do a search for your keyword
there are others
make sure you consider all the important valuation criteria for a domain, such as age and how google sees the domain, keywords, brandability, how perfect it fits your project, etc..... for me, how google sees the domain is hugely number one importance, and that covers alot of different possible variables you will have to figure out
