These sites are the real thing. Sure some of them have maybe one or two stories with mature content in it, but then others have it in every story. You browse around and find what you like.
The links are in no particular order. If you want your link removed just ask. If you want your link added email me.

A
Addicted To Backstreet Fiction
A Backstreet Fantasy
A Dreamers Reality
And Stuff Like What?
Annie's Backstreet Fantasies
Alex's BSB Paradise

B
Backstreet Ecstasy
Basement Slut Inc.
Bone McLean's World
Bonedaddy Fan Fics
Backstreet Boys Lover
Backstreet Boys.. Anyway You Want Them
Backstreet Escape
Backstreet Romance
Backstreet Stories
Be The Stage
Berry Delicious Nick Carter Stories
Beyond Belief
BSB Mind Candy
Backstreet Boys Our Sex Toys
BSB Angst
BSB Visual Room
BSBtapestries
BSB Attorneys
Backstreet Candy
Backstreet Bliss....Lolita 2001
BSB Fiction by Becca O
B.B. & Bonez's Storybook
Backstreet Boys Fantasy World

C
Cleen's Crazy Stories
Changing
Chel-Belle's Storybook
Cherish
Chaotic Bliss Fan Fiction

D
Da Backstreet Fantasy

E

F
Fantasy Island
Friendships Ever Changing
Forever Fan Fics
Fiction For The Curious
Fan Fic Fanatic
Fantasy Eclipse
Felicity Fiction
Five Guys..Two Girls..And A Webpage

G
Get Your Fill

H
Heart & Soul
Hot Sticky Nicky Stories
Homecoming
Hidden Chambers

I
Inside Backstreet
I Wanna Be With You
It's A Sweet Fantasy

J
Just Another Victim of Nick's Sexuality
Just To Be Close To You - Backstreet Boys Visuals

K
Kevin Richardson: Visualized
Kyntal's Fan Fiction
Kiwi's Fan Fiction Page

L
LPB&J's Story Land
Lay Down Beside Me
LD's D.I.D. Showcase
Liquid Dreams

M
Mystery Frack & Mystery Lady's Backstreet Fic
Mi Pappichulo, Nick Carter
Missing You
Michelle T's BSB Stories
My Confession

N
Nick Has Cute Feet
NC Daily Dreamer
Nikki's BSB Fan Fic
Not Your Ordinary Fan
Nick's Chick Fan Fic
Nicktendo.com
Nick Stories
Nick Carter's Chaotic Universe
Nick & AJ Fantasy Stories

O
Our Tommy Hilfiger Man
Outta These Clouds
Our Backstreet Pleasures
Obvious Love

P
Panda 'N' Kit Kat's BSB Fan Ficion
Pieces of a Dream
Pure Heaven

Q

R
Reality Fan Fiction by BSBPride2000

S
Stories By Neen
Stories Galore
Sugar and Spice
Suzi's BSB Fanfics

T
The Backstreet Bedroom
The Almighty Visual Index
Tobystef's Fan Fiction
The Backstreet Boys Adult Connection
The Backstreet Hot Spot
That's What He Said Inc.
The Kat's Meow
The Real Thing
Thoughts From The Heart
Thunder Road
Total Seduction
Truely, Madly, Deeply
The Living Room
The Penthouse of Mistress Mulan
The Backstreet Escapade
The Bitter Suite
Tell Me That I'm Dreaming
Tales From Our Crypt
The Usual Suspects

U

V
Visuals Inc.
Visuals4U
Visual Xtasy

W
Walking In The Clouds
When Barbie Meet G.I. Joe
Where Dreams Begin
Wishful Thinking

X

Y

Z