Whether your videos are available to download or directly visible online, these videos are for adults only and it is therefore important to put in place a home page stipulating that your website contains sex videos.
The site ICRA is a reference for good practice and allows you to put in place an adequate descriptive of your site: sex, violence, language...
By including a home page or pop-up and an adequate ICRA descriptive you will protect children from having access to videos with inappropriate content (sex, porn, violence...)