I appreciate the effort you put into this post OP. I haven't downloaded any nude mods for Postal 2, but now I might considering you recommended it.

I've been playing H-Doom lately, a sex themed mod for the Ultimate Doom. While most of the violence has been replaced with sex scenes, it still should have some appeal to anyone with a love for guro and the Doom franchise.

Left 4 Dead and Killing Floor are pretty good gore games, and can presumably be given sex appeal with the right mods, however I can't name any in particular off of the top of my head. Hotline Miami 1 and 2 are extremely fun and violent, and I would highly recommend both if you can stomach the retro graphics. Mother Russia Bleeds is made by the same developers as Hotline Miami, and is another fun violent retro game, although I've only played it for a few hours.