I'm still working out the story and characters and the like, but I'm hoping to go for a lighthearted comedy much like the rest of HDoom.
A new Doom WAD finally lets you have sex with the demons
A bit more NSFW-sleuthing at work led me to this page where you can take a look at art designed for further dialogue and sex scenes.
Doomguy gets a blowjob from a Baron of Hell, goes all the way every which way with an imp, and more.
It features Doomguy grappling to the back of Cyberdemon, somehow here being a quarter of the size of the monster, who stands immobile and flushed with a sincere sexual passion. One of the gifs comes into play very, very soon managing to achieve penetration despite.