A sex educator. A sex positive person with extensive knowledge who is open about sexuality and has a career educating others. Sex nerds include Violet Blue, Dan Savage, Annie Sprinkle, Audacia Ray, Dr. Ruth and others. Sex nerds publish in print, blogs, old and new media, give talks, seminars, etc.
SN: I can't decide what I want to write my next book about.
EG: What are you thinking?
SN: Either 'Sexy Conflict Resolution' or '101 Greatest Analingus Techniques.' Then again, I've always wanted to do a photo book on condom package design over the years.
EG: You're such a sexnerd.
Text messages having a sexual tone, but for nerds. a nerd sexting conversation would include, for example, innuendos utilizing math, science, proper grammar, emoticons, and good vocab words.
Playing Dungeons & Dragons or WarHammer or similar games. Does not include computer games.
Stems from the fact or prejudice (depending on who you are) that "normal" people don't play these games while nerds don't have sex, therefore retarded logic suggests that these games are the nerd equalent of sex.
I may not be having sex, but at least I'm having nerdsex!
Cool guy: "My girlfriend is so hot and puts out everynight! Unlike your geeky girl you stupid nerd!"
Nerd: "We have nerdsex, and that's way better!"