Trying out some more exotic options

Now that he had finished loading sticky semen directly into his sister's forbidden snatch. Mark reviewed exactly what kind of options he had with master PC. He hadn't really thought about anything more than the most basic stuff turning his sister into a stereotypical curvy Goth was basically something out of his favoured porn, but the reality was Mark had been jacking himself off to all sorts of stuff for many years. Naturally his most prevalent fetish right now with seeing his sister with a swollen belly watching the child that there lurid forbidden union slowly but surely come into the world. Honestly, there were deeper, more forbidden desires, ones he barely gave any thought to. It was going to take a while but in 18 years time... He let out a trembling groan at the thought.

But for now it just occurred to him that he didn't need to limit himself. Instead of a normal vanilla first time he had successfully impregnated his giantess of a sister with a cock that would have looked small on an elephant.

There were so many other possibilities that he previously hadn't imagined doors that his sister had opened for him either by tweaking his sexual preferences all by showing him just how amazing it was to have someone else transform your body.

There were a whole bunch of interesting options and he has started to explore them when Jill finally recovered enough to think rational thoughts.

"Hey there sleepyhead," he said affectionately petting his lap and encouraging her to sit in it.

The gorgeous naked giantess reluctantly shrank down to something a little bit more manageable. She was still maintaining the impressive hourglass but at least not planning on breaking the newly repaired computer chair again.

"I was thinking, after your little show we got a whole bunch of more exotic options that we can try," said Mark gently tweaking her nipples and stroking her swollen belly as more of his copious semen dribbled from between her legs.

"I was hoping you might get some new sexy ideas," replied Jill seductively clicking the tongue stud against her teeth.

"Oh I've got plenty, but I wanted to have you awake before I made any decisions that might affect us both," replied Mark nibbling on her neck as they scroll down through a few different options.

"I'm hoping we can explore all of these eventually, but I think we should probably try them one at a time before we combine them," said the perverted boy gently sliding his cock along the outskirts of her lower lips.

On the screen they seem to be a family of fetish trees each one leading to a different set of options.

Stereotypes, Mark had already enjoyed turning his sister into the kind of Goth who would happily bear her brother's children but there were lots of options they could explore potentially not just for her a cornucopia of sexualised lifestyles were just waiting for them to choose.

Furry: this was one of Jill's selections becoming an anthropomorphic animal was definitely pretty perverted especially when for anatomically accurate animals. If they chose to try that first there are a whole bunch of interesting options not all of the mammalian.

Gender swapping: Both of them had an interest in this, while Mark definitely identified as a man he had always been curious about how sex felt for the other side. Jill seemed rather keen to let him experience the pleasure of being on the receiving end and before her pregnancy started showing they could thoroughly enjoy slutting up together.

Size play: this one was more marks idea breeding his giant sister had made him wonder how it would feel to have her be 6 inches tall, or maybe rope in the rest of the family for some real fun size games.

Extreme body modification: this one was kind of a little bit racy. With his sexual preferences expanded Mark wondered what it would be like to mix and match. He could give himself breasts or his sister a massive cock to match his, they didn't have to limit themselves to normal human proportions provided they were clever. Something told him that someone out there he'd already done this but he felt like there were many more options that he could explore with his perverted sister.

After a bit of conversation sinful siblings had finally made a choice sharing identical perverse grins the siblings turned lovers finally decided to....