Lots of fun

As Ben looked over the Alien he realized she looked a bit like his sister Sue. But aside from a few minor differences it was really a female version of himself. He gazed at her perfect body with large and perky breasts, blue eyes that matched his own, and long, silky brown hair. He couldn't wait to explore her body and he felt his cock start to grow as he began to fantasize about seeing her writhe beneath him as he fucked her.

The Alien smiled as she approached him and saw his throbbing cock grow larger. As he wrapped his arms around her, she pressed her lips against his and they kissed passionately.

Breaking the kiss she said, "This is the perfect opportunity for us to see what human mating is like and now that I have taken the form of your female self you must be dying to try it as much as I am. You ready?"

He nodded

"Good because you are going to love what I have for you." Pushing ben to the ground, she lay on top of him and her hands went down to his cock while he began to grasp her perfectly shaped hips.

She had him lying on his back with his throbbing cock pointing up to the ceiling. She quickly straddled his hips and had her dripping pussy hovering above his dick. When she pushed down, he felt his cock enter her hot, wet, silky smooth cunt. She felt warm and tight but when her pussy began to vibrate he quickly realized he was inside more than just a normal human pussy.

As he felt the walls of her tight pussy begin to vibrate and massage his cock as if they had a mind of his own he groaned, "Oh god! That feels amazing!"

With a grin the Alien replied, "I told you Ben... you will enjoy this as much as I will." Moaning with pleasure, she rocked back and forth and ground her hips, fucking me for all she was worth.

As she continued to ride his cock, Ben couldn't help but fantasize what it would be like for his sister to be atop him. Sue was his deepest, darkest fantasy, that and the combination of feeling her amazing superhuman cunt grasping his cock and her expert movements he knew it wouldn't be long until he was ready to cum.

Looking into his eyes, the Alien saw his desire and fantasy. She smiled and said, "I see that in this form I remind you of a female human you like who has the same parents as you... what is she called in your language?"

Shaking with disbelief Ben replied, "Oh... um you mean my sister?"

"Yesss" She hisses as her pussy tightens around the head of his cock. She smiles and says, "I can sense that you really are attracted to your sister aren't you? You want her as your mate..."

"What? Uhhh... no I don't..." Ben replied nervously

Grinning deviously the Alien replied, "Shhh it's ok Ben? I sense that it is a big taboo among your people... Mmmmm love your cock" She says as she wraps her hands around his neck and grinds her hips in a circle onto his cock before continuing... "But we do it all the time in our race...."

"Ohhh fuck.... feels so good" Ben moans as he dribbles a little precum inside her vibrating pussy.... then feels it get quickly sucked up into her. "Oh god yes... I want my sister so bad! I love her so much!"

"Mmmmm I felt that little bit of cum... bad boy..." Peering deeper into his mind, she continued, "Mmmm but thats not all I see... you want to impregnate her don't you?"

"Mmmm fuck..." Ben moans, shuddering with desire.

"With the technology we have we can make this happen between you two have little problems.... I see the idea really excites you?

"Oh god yes!" He cried out.

"And the more excited he is right now the more sperm he will ejaculate in me...." She thought to herself.

Grinning wider an idea popped in her mind as she began to ride him harder and faster. Drawing from his memory and DNA she turned into an exact model of his sister. Noticing his shock, she smiled and moaned loudly, "Mmmm that's right Ben, I'm just like your sister Sue!" Grasping his hands and placing them on her bouncing breasts she continued, "Yeah these are just like your sister's Ben... wouldn't you love to feel hers too? Feel your own sister's cunt wrapped around your cock??

His cock throbbed and he groaned with desire at the thought of fucking his sister.

Laughing the Alien continued, "Oooo it looks like you do... tell you what Ben... you give me your cum and I'll make sure the next time you see her is when she's begging you to fuck her and give her your cum...."

'Oh god! I'm gonna cum!" Ben shouted when he felt his orgasm near.

With his release near, the Alien grinned with the thought of her plans being completed and grew excited at her impending fertilization. Grinding her hips she replied, "Mmmm thats right Ben! Cum inside me! Give me your seed!"

Grasping her hips, he thrust his dick deep into her body and shot a massive load of cum inside her gripping pussy. As rope after rope of cum shot from his cock, her pussy walls began to massage his shaft, milking him of every drop of his sperm.

"Give it to me Ben!!! Breed me!!!" She screamed out as he filled her with his seed. When he was spent, she rolled off him onto her back and raised her hips so none of his sperm would leak out.

As he looked up at the Alien she was grinning with satisfaction. Caressing his cheek she said, "You see Ben... we suffering large infertility amongst our race so I hope with your seed my people will bear many of the most intelligent and advanced hybrid human children you can imagine, continuing our race. In return I am going to keep my promise to you about Sue."

I heard the doors open and slam shut and the sound of Sue's heels clacking against the floor. Seeing me naked in a space ship she shouted, "Ben! What the hell is going on?? Suddenly as the Alien caressed my balls I felt reinvigorated and as if I hadn't cum at all. Looking into her eyes for a second, the Alien grinned before looking down at me and whispered deviously, "Well Ben... I hope you're ready to fulfill your darkest fantasy... because it appears she shares it with you..."