Uuhmm... take a wild guess.

The **** of sensations was too much for Monica. Wrapping her arms around her barely conscious son, she began thrusting her twitching cock into him from below.

"Oh god, sweetie, we shouldn't... hnaaah... do this, but... Ah! You're so tight!"

To Adam, who was recovering from an orgasm a whole day in the making, the pleasure was indescribable. He could only moan and gasp loudly with every thrust of his mother's dick. Her forceful thrusts were bouncing him on top of her, and with every drop he slammed into her crotch, her prick driving deep into his pussy, making him cry out in bliss.

Both of them were riding the high of pleasure, so neither noticed the changes triggered by Adam's orgasm at first. Only when the space between their upper bodies became more and more crowded did Monica look down and see that Adam's small, A-cup titties were swelling surprisingly fast, filling out the nightie. She took one hand from Adam's back to caress the side of one through the silk, prompting a loud cry of pleasure from her son.

"Ooooh yes, mom! Touch it more," he moaned, arching his back to give her better access to his burgeoning rack. Monica did not have to be asked twice - using her free hand, she cupped the rapidly growing boob and squeezed it, causing Adam to squeal in bliss and his pussy to spasm around her cock. The vice-like grip was almost to much to bear. Monica slowed down her thrusting, not wanting to cum to early. Her son's pussy felt way too good to have this end so soon.

Adam had by now calmed down enough to take a more active part. Monica's fat cock-head rubbed his insides deliciously, the shaft stretching his inner walls. He put his hands on his mom's shoulders to raise his upper body and began gyrating his hips on the pulsating invader in his cunt. Monica stopped the thrusting of her hips to just give herself to the experience of the tight snatch around her cock. Adam's boobs already filled out the cups of the nightie, throbbing nipples poking through the thin fabric.

"God, mom, you're so... ah! So big... haaah... so deeeep," Adam managed to squeak out, between lustful gasps and moans. He began raising and dropping his hips slightly, the minuscule movements already enough to drive him wild. But then Monica grabbed both his tits and began caressing the swelling flesh, thumbs rubbing over his nipples. White-hot lances of pleasure raced through Adam's being, combining with the pure bliss from his crotch, and with one last, **** slamming down of his hips, he **** his mother's prick deep inside him and came hard around the burning hot meat inside him, his moans having turned into unabashed screams of pleasure. Adam's breasts gave one last surge of growth, their upper parts now bulgin softly over the cups, quivering with Adam's climactic twitching.

Seeing her baby shudder and convulse on top of her was almost to much for Monica as was the twitching and spasming pussy milking her dick, making her tool tingle and throb, but with a lot of effort, she was able to hold on and instead used the opportunity to free his jiggling tits from their cups, pulling down Sarah's nightie. They sagged a little without the support, but remained remarkably perky, their connective tissue having just grown in. They were capped by slightly bulging, light-brown areolas and nipples that could give pencil erasers a run for their money size-wise. The feeling of fabric sliding over his breasts and rubbing along his nipples intensified Adam's orgasm, once the feeling subsided somewhat, he still didn't have enough from the turgid pole inside him.

"Mom... agh! I... ungh... need you to... haaannh... fuck me. Fast and... oooh, hard, make me CUM," he babbled, bouncing almost lazily on his mother's cock. Hearing her baby begging her to fuck him was all Monica could take. She pulled him close to her own bosom, the stimulation on his heaving breasts making Adam moan, and them rolled both of them over until she was on top. Monica straightened her upper body until she was kneeling over her son, dick still buried deep in his snatch. She then grabbed his hips for leverage and stared in Adam's eyes.

"Oh yes, do it! Give it to meee, ah! MOM!" Adam screamed as Monica started railing his cunt as fast as she could, his juices squelching and spurting out with every thrust. This was what he wanted. The iron-hard rod messing up his insides felt heavenly, his new boobs bouncing uncontrollably from the rough fucking - he was loving every single second of it.

"Ah! Ah! Yes! Yeah! Ungh! FUCK!" A barely coherent string of curses, moans and gasps left Adam's mouth every time his mother buried her dick to the hilt. Monica herself was grunting and groaning with lust and exertion. If her baby wanted her to fuck him, she'd give him the best sex of his life! And she was obviously successful: Adam could not remember ever having felt this good. Not even the cucumber came close - the hot, throbbing cock spearing him eclipsed the vegetable by far, despite being a bit smaller. But the exquisite shape made more than up for that.

"Oh Adam, baby, I feel it coming... Ah! Do you want it? Do you want mommy's cum?" Monica stammered, thrusts becoming erratic.

"Oh god, not yet, I'm so close, I'm so close," Adam gasped, but it was too late. After two more forceful thrusts, his mother spilled her seed deep inside him and kept pumping throughout her climax, blasting shot after shot inside Adam's twitching pussy. And finally, the feeling of burning hot jizz filling him drove Adam over the edge. His third climax of the night was by far the biggest.

"Nnaaaaah, yeeaah!" Adam screamed out his bliss, back arching, body shaking, toes curling, eyes rolling back in pleasure. His snatch clamped down so hard that Monica was unable to pull out her sensitive prick, making her double over in a mix of pain and pleasure, her face buried between Adam's shaking breasts, effectively motorboating him. He thrashed below his mother, throwing his head from side to side, and grabbed fistfulls of the blankets as if holding on for dear life.

After almost a full minute, his cries finally let up and his orgasm subsided, replaced by a warm glow all throughout his body. Monica pulled out her slowly softening cock with a soft 'pop', her cum slowly leaking out of Adam's snatch, and laid down beside him, taking him in a warm embrace. Adam snuggled back, nuzzling his head under her chin, both drifting off to sleep exhausted and content.

Neither of them noticed the faint sounds coming from Adam's butt and thighs.