Changing in-game sounds to mature clips. Examples include replacing tongue-grab sounds or music with adult-oriented audio. How to Install Adult Mods
The distribution of adult mods brings up the complex issue of platform moderation. The Steam Workshop has specific guidelines regarding "Adult Only" content. While Valve generally allows for a wide range of creative expression, explicit sexual content often exists in a grey area. Visibility vs. Accessibility left 4 dead 2 adult mods