Slight enhancements:

Percy had breakfast together with his girlfriend Annabeth, as she was currently visiting and sleeping in the guest room of his apartment. He didn't understand why the female didn't want to share a room, it's not as if they haven't had sex already – but Annabeth had said she wanted to have her own room too.

Venom had been silent while Percy was eating, enjoying the nutrition he received through the male's body, but when the young demigod went to wash the dishes and Annabeth moved towards the bathroom, he started talking. Venom asked Percy when they would fuck the pretty blond-haired girl and how they were going to do it. He talked about the different possibilities they had and how amazing it would be for both Percy and him – creating hot images in the mind of a very horny and needy Percy Jackson.

"OK, OK!" Percy whispered – "Annabeth won't leave for a while and we can fuck her as soon as she is out of the shower, but you need to keep a low profile for now. I don't know how she will react to you." the black-haired male said sternly while he felt his cock already rising within his shorts.

"OK, boss. Will do." Venom chuckled as he noticed how horny and needy his new host was at the moment. "Go to her room. I'll make sure you are prepared." the deep voice said within his mind. Percy just wanted to ask how Venom would do that, when he felt the same rings from before breakfast around his already hardening cock.

"Fuck…" Percy groaned and made his way towards Annabeth's room while Venom started to pump his cock to get him fully erected and nicely hard. The black-haired male undressed quickly and laid down on the bed, watching how Venom caused the rings to slide up and down his hardening and thickening shaft with great fascination. "You are quite well equipped, my host." Venom said "But I will make sure to enhance these features a bit."

Before Percy could reply, the bathroom door opened and Annabeth stepped into the room – she was naked and still slightly wet. Venom immediately retreated before the female could see him, leaving Percy's dick to stand proudly on his own. "Percy!" the blond-haired girl breathed out as soon as she saw her sexy boyfriend. "Happy to see me?" she giggled, while watching his twitching erection. "Always, baby girl. I'd be a lot happier though if your needy cunt was around my cock."

Annabeth moaned and made her way towards the bed. "I've hoped you would do something like that. I got quite horny during breakfast and wanted to take care of it in the shower, but my need only worsened." she muttered. "I am already dripping with arousal, Percy. Do something about it!" she said, while getting on top of Percy's groin.

Before she sat down, the male could see in between her spread legs and noticed, that what she said was true – the demigoddess was horny and wet, all for him. Annabeth bend down and grabbed his hard shaft to help guiding it into her and sat down, causing his length to vanish inside of her pussy completely. "God, Percy!" the female exclaimed with a slightly painful look on her beautiful face "Did you grow even bigger? Your tip is pressing hard against my womb."

The green-eyed demigod smiled, silently thanking Venom – he was big on his own, but Venom seemingly enhanced his length by just a bit. It caused his cock, which normally slightly touched Annabeth's womb when she was sitting onto his groin, to press hard against it now.

Slowly, the girl started to ride him and both Percy and Venom groaned at the feeling. "Fuck, that's nice." Venom rasped out and Percy grunted in agreement. Annabeth smiled and sped up a bit, while still continuing her rocking motion. Again and again she moved up and down, while shoving herself back and forth a bit too – it created a heavenly feeling inside her tight pussy and the girl knew, that she wouldn't last long.

"Percy…" she breathed out and said male told her to restrain herself as long as she could manage. The female moaned but kept moving, concentrating on not coming. Annabeth did her best, but it was only moments later, when she neared her orgasm – Venom sensed it and warned Percy about it, who bucked upwards and plunged himself as deep into Annabeth as possible when they both came in unison.

While Annabeth was riding her orgasm and breathed heavily, Percy managed to turn them around – Annabeth was now laying on her back with Percy deeply seated between her spread legs.

"How about giving you a bit more thickness, now?" Venom asked and Percy nodded. He felt how Venom moved from the tip of his cock, from where he had given him some extra length, to cover him completely and slightly moving more outward to thickening his still hard shaft. As soon as this was done, the young and powerful demigod started to move – pushing his hips back and forth – not reaching just as deep as before but stretching the tight pussy of his hot girlfriend more than previously.

The blond-haired girl came down from her high and only now noticed the new position. She wanted to comment on it, but couldn't, as Percy pushed forward once again. "Gods, Percy!" she exclaimed and moaned loudly. That was all Annabeth managed to say, as she felt herself being stretched apart. 'How is he doing that? He was slightly longer before and suddenly he is thicker. How?' Annabeth's mind run wild but soon was shut down by the sensation of Percy's cock, rubbing over every inch of her sensitive inner walls.

He had never filled her out as good as today and at some point it even felt as if his dick was slightly changing shape within her - pushing upwards against her g-spot in a position he shouldn't be able to do it. The girl couldn't comment on it though, as she was fucked so good, that she was quite literally breathless.