The Family Safety Filter is enabled by default, but may be turned off, there is two ways to do that:
Open the homepage and just click on the "18+/Sex" icon:
To activate the filter, click on the icon again.
a) Open your account settings by clicking on your avatar/nickname (in the top right hand corner) > Settings.
b) Switch to the tab > Browsing
c) Uncheck the checkbox > "Family Safety Filter" if you want to disable it and click > Save button to save your settings.