You want to see? Join. Contact the maintainer (quecojones) or post here.
You must be 18+ and your DOB must be visible on your info page. If, for some reason, you don't want to display your DOB on your info page, contact the maintainer to see what can be worked out.
EDIT: The LJ community management system has been changed so you have to click on the "join this community" link on the community's info page to join. The LJ system will send me an email with the request and I'll either accept/deny the request.