Use the real thing...

Alyssa: "Well, I don´t have a dildo, and besides, I´d really want to get the instructions, so I can do it for you better, Matt" she says with her horny eyes and low voice, hinting that you might be getting a blowjob soon. "I just need the practice..." she says, eyeing Sid´s cock and balls.

Against your better judgment, you decide to agree with Alyssa. "Okay, since it´s just her mouth, it´s not cheating, right?" You ask Sid.

Sid: "Right. Just her mouth."

Sid and Alyssa change places, Sid now laying on his back, massive cock perched against his stomach. Alyssa straddling his legs, grabs hold of Sid´s cock and starts giving it a few strokes, memories of the shower they took just a few minutes earlier flood your brain, except now you are seeing it for real. Now she is trying to make him cum. Your own cock is pathetically lying, flaccid in you own pool of cum that has started to stream down the sides of your torso.

Sid: "Now, I like to have women start with getting to know the area intimately, start by sucking my balls while you stroke me." Alyssa does as he says, taking one of his big balls in her mouth while she strokes his cock with one hand, moaning a little as she does so, then switching to the other ball after a little while.

Sid: "Good, very good, now lick from the center of the ball sack, where the seam is, and up the shaft, at your own pace." Alyssa´s tongue starts licking exactly where he said to, traveling for what seems like ages up Sid´s erect, bare naked, pulsating cock, eager to cum from all the eroticism that has taken place tonight.

Sid: "Yeah good, once you reach the top, take the head in your mouth, watch for the teeth, we want to mimic the feel of a pussy. Use your mouth pussy on my cock, Alyssa, use it on my cock until I cum. Suck me."

Alyssa´s cheeks went red at the dirty talk from Sid, and you realize that she hasn´t looked at you at all since the blowjob started, she is completely focused on pleasing Sid right now, locked in to his eyes as he tells her to suck his cock. Alyssa is now working the head of his cock in her mouth and her cheeks start to suck a little bit inward, trying to keep all the saliva and precum that is in her mouth from leaking out.

Sid: "Yeah, now on each stroke try to go as deep as you can with your mouth pussy without inducing the feeling of puking. With time, and practice, you will be able to deepthroat me. Try and grab my butt to gain more leverage on my cock, with both hands, leave your hands off the cock when you´re sucking for real. A mouth pussy shouldn´t need hands to make a cock cum."

Alyssa moaned loudly with Sid´s cock stuffed in her mouth and started to really suck him for all that he was worth, although not fitting the entire cock in her mouth, it was more like just less than halfway in.

Wait, time and practice? He´s going to have her suck his cock again? I thought this was a one time thing! You think to yourself, unable to vocalize it over the sound of Alyssa sucking Sid´s massive cock right in front of you. You are frozen in place in the sheer taboo of it all, your girlfriend buck naked, feverishly sucking a strangers cock in order to get better at engaging in sexual encounters with you. Your own penis, which is like a third of what Sid is packing, is hard again, and painfully sensitive, but you jerk it nonetheless as you watch your girlfriend suck, suck, suck and suck Sid´s cock for what seems like ages, her hands clasping his butt, shoving his cock as far as it goes without causing her to gag.

"I´m going to cum, I´m going to cum fucking loads!" Sid says loudly, you worry it would wake up the roommates. Alyssa stares in Sid´s eyes as she continues sucking him.

"Don´t stop, don´t you fucking dare stop, suck my cum out of my balls and swallow it all, swallow all my cum, Alyssa!" Sid now practically yells, but he doesn´t put his hand on her head, he trusts her to keep sucking, which she does. She keeps going, and seems to get his cock just a little bit further down her throat, maybe the dirty talk helped her get it further. Sid is now thrusting rapidly upward into Alyssa´s mouth pussy, while she is still clasping his butt cheeks to keep him in place. This goes on for a few more seconds until Sid, sweaty, hairy, and with his cock deep in your girlfriends throat, groans deeply as his cock spasms too many times to count, first spasms are rapid, then they slow down, but it must have been about fifteen to twenty spasms. Sid groans and moans for about 20 seconds as he ejaculates rope after rope of strange, homeless cum down your girlfriends mouth pussy.

Sid: "You´re doing great, Alyssa, swallow it all, you deserve it for being such a good fucking girl...."

Alyssa´s eyes are red, and seem to be smiling as she makes gulping noise after gulping noise, absolutely guzzling down Sid´s cum as fast as she can. Finally once Sid has stopped thrusting, some cum mixed with saliva drips down in between Alyssa´s mouth and Sid´s cock firmly wedged in her mouth. She brings her mouth fully off of his cock and more cum drips down "oops, sorry" she says as she goes down on his balls again and cleans up the cum that she dropped.

You are absolutely fucking stunned that you cute, petite, large breasted girlfriend just did that to a homeless stranger, before ever even showing you her body, much less giving you a blowjob. You feel conflicted, but at the same time, your cock is raging hard and you are jerking yourself off again.

Alyssa: "That was amazing, and so hot! Thanks for teaching me, Sid! I can´t wait to learn more, right, Matt?"

You: "Yeah.....sure" You say, not fully realizing that you just consented to Sid teaching Alyssa more about sexual encounters.