Note: This story was dynamically reformatted for online reading convenience.
 
 Trading Places, by Medea (medeafk@hotmail.com)

   "What's this?" Isabel asks, slipping up behind her boyfriend, Mark, who
sits at his computer.  "I thought you said you were working." She peers at
the images of scantily clad women on his screen.

   "This is for work.  My latest client is a photographer, so I'm trying to
decide the best way to arrange these photos for his website," he answers.

   "Oh." She leans in closer for a better look.  "Are you sure you don't
mean that your client is a pornographer?"

   He laughs.  "Theoretically, this is fine art photography, though some of
the props in these pictures make me wonder.  Take a look at this one." He
pulls up an image of a lean Asian woman in a short black dress, who has
something sticking out under the hem in front.

   "Wait, is that what it looks like?"

   "I think it's a strap-on."

   "Oh!  That's interesting.  She's so feminine, otherwise."

   "I think it's kinda sexy."

   Isabel looks at Mark questioningly.  "How so?"

   "Hmm, just that she has the best bits of both sexes, right there on one
body."

   "I, uh, didn't think you were interested in penises other than your
own."

   "Not usually, no.  But a facsimile attached to an attractive woman,
that's something else."

   "I'm still not sure I understand.  Tell me more?"

   "Not right now," he says, shooing her out.  "I need to get back to
work."

   The next evening at dinner, she brings it up again.  "So, about that
picture...  What exactly is it that you like?"

   Mark thinks for a minute.  "It's the role reversal, I guess.  I'd like
to see what it's like to switch places and be penetrated by a woman,
instead of the usual way around.  I think I'd really enjoy being taken. 
And the photograph makes me imagine that."

   "Wouldn't that be uncomfortable for you?  I mean, I thought most guys
didn't like anal penetration."

   "Some men like it.  It doesn't have to hurt, even, if you go slow."

   "Hmm.  So this is something you want to try, then?"

   "Possibly, yeah.  What do you think about it?"

   "I'm definitely curious.  Want to go shopping this weekend?"

   On Saturday afternoon they drive to a small sex toy shop that has a
reputation for being "couples friendly".  It's pleasingly clean and
well-lit, and the product shelves have various reviews and advice to help
customers select the best item.  Mark and Isabel wander over to the display
of dildo harnesses, and select one with black leather straps that looks
like it will fit comfortably.  Then they move on to the selection of
dildos.

   "The flesh colored ones look even more unnatural than the bright
colors," Isabel says.  "Let's get red or purple or something."

   "How about blue?" Mark asks, holding up a long, thin ultramarine
silicone dildo.

   "Perfect."

   They grab a bottle of lube from one of the other displays and then head
to the counter to pay.

   Returning home, the purchases are set aside until evening.  Their
anticipation grows throughout the rest of the day, and Isabel whispers
suggestions about what she will do to him later that night, when Mark comes
into the kitchen to see if she needs help cooking.  After dinner, she
disappears into the bedroom while he reads email.  When she returns, she's
wearing her sexiest satin nightgown, with nothing but the strap-on
underneath.

   She wanders downstairs to his office, and nearly starts laughing when he
turns around to look at her.

   "It feels unbearably obscene, having this poking out in front, but I had
to try it this way," she tells him.

   "Mmm, I like it even better than that photo."

   "You'd better!  Want to come here and see what we can do with this?"

   He gets up from his chair.  As he stands there with his arms around her
she rubs the fake cock against him.  "I always love it when you grind
against me," she says.  "How does it feel when I do it to you?"

   "It makes me want to find out what else you can do."

   Looking slightly predatory, she leads him to the bedroom.

   Once there, he undresses as she dims the lights.  She walks up behind
him as he's finishing, and wraps her arms around his chest, pressing
herself against him.  "Hmm, I'd need a step-stool to take you from behind
like this.  Too bad."

   "I'm sure we have one somewhere."

   "Maybe next time."

   He turns around to kiss her, enjoying the feel of smooth cloth and the
hardness between her legs pressing against him.  She breaks away from him,
and moves towards the bed.  He follows.  They lie down, side by side,
kissing wetly.  He reaches for the lube which is lying ready on the bedside
table, and hands it to her.  "I think you should start with your fingers,
first."

   "This probably isn't the best position.  What if you get on your hands
and knees so your ass is open to me?"

   He rearranges himself, and she pours lube onto her hand, lubricating her
fingers.  He breathes deeply, trying to relax.  Slowly, she pushes at his
asshole, sliding her index finger inside him, up to the second knuckle. 
"How does that feel?"

   "A little odd, but okay.  Wait a minute before going any deeper."

   He relaxes a little more, letting her further inside.  She tries
wiggling her finger slightly, which elicits a moan from him.  "Ohhh... 
mmm, I think you can do a second finger now if you're careful."

   She pulls out and then pushes at him again, this time with a second
digit.  She feels his anus dilate to accept her as she slides back inside.
Then she begins to stroke her fingers in and out, enjoying the sound of his
breathing as it becomes more ragged.

   Thinking that he might be open enough now, she asks, "Ready for the real
thing, for me to fuck you with my cock?"

   "Mmm, Bella, yes, give it to me."

   She lifts the nightgown to expose herself, and applies lube to the
dildo, rocking her hips back and forth a little as she strokes it, trying
to imagine what it would feel like if this were her own flesh, attached to
her.  The way the base of the dildo presses against her stimulates her clit
just enough that for a moment she can believe it's real.

   She gets onto her knees, positioning herself behind him, and uses one
hand on his hip and the other on the dildo to guide them together.  The tip
enters him, and she holds it there for a moment before going further.  He's
moaning loudly now, every time she moves, more vocal than she's ever heard
him.  She pushes a little more into him, hands firmly on his waist.

   "Fuck me Bella," he groans, and she slides the rest of the way in.  She
fucks him slowly, firmly, as he strokes his own cock, now rock-hard.  She
twists her hips a little, feeling the grind against her clit and letting it
grind back into him.  Holding him, controlling him, it's in and out and in
again and it feels so good, better than she imagined.  He cries fuck me,
fuck me, repeating like a chant, and then he's coming with a hissing
yessss. She can feel him twitch, and he falls forward onto the bed,
exhausted, dislodging her from his ass.

   She sits quietly for a moment, watching his sweaty body lying on the
bed, pleased with her work.  He turns over to look at her and smiles. 
"Mmm. That was good."

   "We can do it again.  I don't have to wait for this thing to get hard,
you know," she teases.

   "Uh, no.  I get the impression I'd be a complete wreck before you even
started to get tired."

   Isabel smirks.  "Well, then I think I'll go clean this off."

   "Want some help?  A shower is sounding nice, right about now."

   "Oooh, good idea.  Wash my back and I'll wash yours?"

   "You're on."
   Laughing, they get up and head for the bathroom.