You watch from start to end

You step inside the dark room, and close the door lightly behind you. Leaning against
the wall you take in the sight before you.

...

The covering blanket soon comes off, and the two people emerge from the sheets.
Jane slowly rides her partner, her body facing away from him as she rocks her
hips up and down over the man's hard cock. Leaning forward, presses her breasts
against the bed as she continues to fuck her partner up and down, using nothing
more than her hips, the man simply laying back and enjoying his good fortune.

Jane's face is against the bed as she concentrates all she has on fucking the hard
cock deeply buried within her cunt. Up and down she rocks, gasping in pleasure.
"Ooh fuck yes, you've got such a hard cock!" She groans. "Such a good hard
cock!"

"Oh god," moans the man as he feels his cock caught in a very tight vise of a pussy.
"Mm, should I pull out and put on a condom?" groaned the man. "I wouldn't want
to get you pregnant."

"Mmm, that's ok hon. I think I can chance it just this once." said Jane

With that thought, the man began to pound Jane like it was his last fuck on
earth.

"Mm, yes, that's it. Come for me!" yells Jane. At that moment, she looks up and
sees you looking at the two of them. For a moment you wonder what you should do,
when suddenly Jane grins and winks at you. Seeing you frozen there, Jane's
face twists into a devilish look.

She begins to groan loudly, exaggerating you can tell, as she fucks her partner
faster and in time with his thrusts. "Yes, yes, fuck me, fuck my tight, wet, pussy!"
She groans. "Another man, wanted to fuck me earlier, but you beat him to it."

The man groaned at this knowledge, his thrusts becoming more erratic.

"He wanted to woo me and bring me to bed. Fuck me. But you beat him to it."
Jane winks at you. "He wasn't man enough to take me, and now you get to
reap the rewards ... my pussy!"

"I'm going to cum soon hon, where should I come?" gasped the young man,
his hips twitching frantically as he struggled to hold back.

With a devious look, Jane stares at you, and whispers quietly, "You can cum
in my pussy, babe."

Not needing to be told again, the man groaned and gripped Jane's hips tightly as his
hips thrashed about and finally laid still as he began pumping load after load
inside Jane. The sight of the erotic coupling starts to get you hard, despite yourself.
Watching another man blow his load where you should have been, is too
much for you. You stand frozen in place, and growl in anger at being beaten
to the finish line. If she weren't protected, it would be his load not yours, that
would get her pregnant.

Finally, the man finishes and pulls out of Jane with a pop. She continues to smile
at you, not noticing the man or that he had finished. After a few moments, she
begins to get dressed and gives her man a kiss. She walks past you, and gives
you a kiss on the cheek.

You snap out of your reverie and follow after Jane into the hallway, but by then
you notice she is gone.