Fight him

You are furious that this shape-shifting impostor would command you to spread your legs like some common whore. You are a virgin warrior and your oath demands you defend your chastity. Instead of answering him with words, you let your sword speak for you. You swing Saint Magdalena’s sword in a practiced arc. The doppelganger copies your actions and counters your attack.

“Aww, you think you have a fighting chance?" The doppelganger sneers. "How cute."

You attack again and again. Each time, the doppelganger counters your assaults by acting like your mirror image. Dueling a naked male version of yourself is very distracting. Most of your attention is pulled towards that dick of his that keeps flopping around. Worse yet, the longer this fight lasts, the bigger and harder his dick becomes. This fight is really getting him excited.

Worse is your own arousal. It grows with each **** clash of blades and each brush of his hardness against one of your legs. Is it simply the adrenaline thrill of battle or... the fantasy of your defeat?

Suddenly, you place your foot on a wet stone and lose your balance. You fall backward and hit your head to the ground. The doppelganger makes good use of your momentary disorientation and kicks the sword out of your hands. Then he turns you over so you lie with your stomach on the wet forest floor. You come back from your confusion only to feel the doppelganger’s weight fall on you and pin you down.

“I warned you that my victory was inevitable," hisses the doppelganger. “You should have just accepted your place as a breeding vessel. It would have been much more enjoyable.”

The doppelganger presses his hips against your bottom and his cock falls into the warm crevice between your cheeks. You can feel his rod slide between the length of your crack as if he is trying to fuck buttocks.

“So very soft and warm.” he groans. “I could enjoy this without even entering you and spray your lovely hindquarters in my seed.”

"Do it then," you growl through gritted teeth. You leave unspoken that such an act, though disgusting, would not cost you your chastity.

“Oh, no," says the doppelganger, dashing your hopes. "I cannot breed you with my cock spraying your lovely bottom. I need your womb for my purposes.”

The doppelganger pulls his cock back. You can feel his cockhead slide down, past your anus, and start poking your slick folds.

“No! Wait!” you cry. “I am a sister of the Burning Rose. I have to remain chaste for my goddess.”

“Sorry, sweet one.” The doppelganger apologizes. “But I don’t care about your religion.”

Your evil twin thrusts forward and sheaths himself into your pussy. As his member breaks your maidenhood, you feel a sharp pain, and know that your spiritual connection with your goddess is severed forever.

It’s over, there is no use fighting back any more. You lay there on the forest floor, not fighting back any more, while the doppelganger gives your virgin pussy a pounding like it has never received before.

“You’ve got a great pussy, sweetheart.” Your evil twin says. “It’s nice and tight and warm.”

With every thrust, you feel your walls expand and give him access to your sanctuary. You feel like your cunt is betraying you. Like it is finally giving in to all that pleasure you had denied it.
Every time he pushed inside, your breasts are pushed against the forest floor. Your aroused condition has caused them to become sensitive and now they too are rebelling against you.

When the doppelganger increases his pace, you can’t hold it any more. You raise your head from the dirt, open your mouth and give voice to your pleasure.

“Feels pretty amazing to get fucked by yourself, doesn’t it.” The doppelganger says.

You want to talk back at him, but the only sound you manage to produce are more moans.

“You like screwing yourself over, don’t you.” The doppelganger says. “To have a man inside you who looks just like you. A mirror image of yourself giving you the pleasure you’ve always wanted. It is like some advanced for of masturbation, really. Tell me, how often have you denied yourself sex in favor of your virginity and made love to yourself.”

The creatures words are filling your head with filth. Yes, you had chances to lose your chastity but denied yourself the pleasure so you’d stay pure. Yes, you played with yourself to satisfy your lust. Yes, you are getting off getting fucked by yourself. All of these thoughts running through your head become too much and you cum like you never have before.
At the same time, you hear the doppelganger roar and his cock belched thick streams of sperm into your womb.

When he is done filling you, he pulls out and stand up.

“If you follow the river downstream, you will come to a bridge. From there you can follow a road that brings you to a human settlement.” Your **** tells you. How considerate of him.

“I’d love to stay around, love. But I’m afraid there’s other women who need some help breeding. Be sure to take care of our baby.”

Then the doppelganger walks into the forest, and disappears.
You stumble back to the river and clean the mud off your chest and face. As well as the semen that had leaked from your quim. Then you continue your journey. You may not be a sister of the Burning Rose any longer, but you still have a mission to get to the high abbey.