Fuck this chick!

"I sure do!" You say happily. "Why don't you get down on all fours, and I'll show you the meaning of sex."

Alexandra stares suspiciously and says: "Alright. I hope you know what you're doing."

She gets down on all fours, facing you and you get up off the couch and walk behind her. While you walk, you get a good look at Alexandra's perfectly proportioned body and already start feeling the blood rushing to your dick. You walk in front of Alexandra's beautiful round ass and take it in your hands. Her puckered asshole is perfectly in line with your cock, which should make this all the more enjoyable. You take your dick in your hand and give it a few strokes to bring it to a full erection. Your tip is covered in precum, as the anticipation of getting to fuck a giant futa excites your mind. You bring the head of your dick to the entrance of her anus and press against it. It doesn't take a lot of **** for your cock to slide, smoothly into Alexandra's ass.

An "EEP!" sound escapes her lips as you penetrate her.

She's tighter than you expected, but still a bit looser than any other ass you've been inside. However, that doesn't stop you from getting to work.

You start moving your hips back and forth, thrusting your average sized cock inside of Alexandra's giant-sized ass. Your dick has never felt anything quite like this before. Her ass presses surprisingly hard against your shaft, but her enlarged insides make it easy to slide in and out of her. As you take Alexandra from behind, you hear quiet moans come from the other side of her. You start applying more **** and speed to your thrusts, and as you do, Alexandra's moaning gets louder as well. It's not long before both of you are grunting and moaning, as you start pounding Alexandra's ass with everything you've got. You feel her hips start to back into yours at the same rhythm of your thrusting. You grab a hold of her toned thighs and start slamming home with all of your might.

You just barely manage to reach her prostate with your thrusts, but that is enough to start getting her hard. Blood starts rushing all through her soft dick and it slowly rises to a full erection, but you have a hard time seeing it because of your position. Nevertheless, you keep smashing her ass until you feel yourself get close to cumming. With a few final, powerful thrusts, you plunge in as deep as you can down Alexandra's ass and unload your cum. You grunt load and shoot 3 big loads of semen in her anus. It covers your dick and paints the inside of her rectum white. You take a few heavy breaths to collect yourself, and then,

Alexandra speaks up "Wait, are you done already? I haven't even cum yet!"

You reply "Just... give me a minute..."

Alexandra puts on an angrier tone and says: "Ohh, no way buddy. You already got me hard, so now finish the job. If you can't, then I'll do it myself."

Before you can pull your dick out of her ass, Alexandra quickly crosses her legs behind your back and around your waist, holding you in place. She starts moving her legs back and forth, practically fucking herself with your dick and not giving you much choice in the matter. Her muscular thighs are powerful enough to move your entire body, making your dick slide in and out of her ass like before. You are still getting over your last orgasm, so the first few minutes of this are really putting work on your cock, but soon enough you get back into it. The second orgasm you experience happens much faster, and you spray another load of cum in her ass. However, Alexandra doesn't stop and continues fucking herself with you. You hope to god she cums soon because you're not sure how much more you can take...

It's been a while of nothing but slapping sounds and tired groans from you, as you experience around 6 more orgasms. You were already pumped dry of semen at your 5th orgasm, so you just struggle at this point, with no chance of escape. Finally, you start hearing faster and heavier moans from Alexandra, and you get a glimmer of hope that you might be freed from her clutches. She starts smashing you into herself faster and faster. Her asshole clenches around you and she lets out a scream of pleasure as she finally crosses the edge of orgasm. She holds you tightly and you can feel the sperm travel through her crotch and shoot out of the tip of her dick. You feel her ass tighten more and more with every spray of jizz, to the point that it starts getting numb. After a minute of cumming, Alexandra's ass finally releases your dick, and so does her legs. You jump free and your soft cock pops out of her cum dripping ass. You fall to the ground in exhaustion and try to recollect yourself.

After a little time out, you stand back on your feet and watch the scene before you. Alexandra is sitting next to the couch, looking playful. You wonder why she isn't sitting ON the couch, but you realize why once you take a look at it. It's completely covered in her white sperm.

You speak up "I'm guessing you liked that."

Alexandra replies "I sure did! Sex felt really great, even with your tiny little normal sized dick!"

You blush a little, but don't take her remark personally.

The speakers turn on and Alan speaks up. "Alright guys, we got some interesting results. Not really how we expected this test to go, but still, great job, the both of you! You can go ahead and get back to your rooms."

Alexandra waves goodbye one last time and walks back to her room, and you do the same. You can't wait to get out of this place and tell all of your friends about the time you banged a giant chick in an underground lab.

You got the "Bragging rights" ending with Alexandra