Fallout New Vegas Nude Skins
Get FOMM first. Fallout Mod Manager, most mods support it, some require it. Also Get NVSE - New Vegas Script Extender - I don't even know what the fuck it is but it's always updated and easy to install, and most mods like it.
Beware of girl type 3
Download Fallout New Vegas Female Nude Skin
Breezes New Vegas Males
Download Fallout New Vegas Male Nude Skin
Nudity in Billboards and signs and even the game loading screens!
Fallout New Vegas Sex Mods
Get FOMM first. Fallout Mod Manager, most mods support it, some require it. Also Get NVSE - New Vegas Script Extender - I don't even know what the fuck it is but it's always updated and easy to install, and most mods like it.
Willow
An excellent companion mod and one of the most popular mods for this game. It's not a sex mod, she has a quest and a storyline and you will interact with her in many ways, eventually making her your girlfriend. In conjunction with the other mods here, you *may* be able to fuck her, but I'm not sure yet.
Ok here are the sex mods. I tried to get these working and take screenshots but I had no luck with anything and I'm giving up for now. Figured I would post the links and maybe take screens at a later time when I don't feel like I just wasted hours of my busy life. One of the problems is the creators of the mods have moved on, and never really finished in the first place.
Your best bet is to experiment, read the comments, etc and be willing to waste time to get this shit to work in any way. I would rather just play the game (which is better than Oblivion and Fallout 3 combined IMO) when I have the time.
FNV Sexual Innuendo
Sex animations. It sort of works. Expect quirks and bugs.
Expand with Humping the Mojave
Animated Prostitution this one has better features (i.e. the hooker gets naked during blow jobs and you only pay her once to do whatever), but there are bugs here as well.