(Assuming Jeffs sisters name is Alice from this point on)
The next morning you are awoken by the familiar sound of the doorhandle being turned. In walks your sister Alice, straight from bed you can guess as she looks really tired.
"*Yawn*, good morning Jeff, hope you slept well. I know I didn't. I'm just so nervous for today."
You recall that today is saturday, which means date-night for Alice. "Im sure it will be fine. You are a loveley woman, how could he resist you?"
"Oh stop sucking up to me Jeff" she says jokeingly as she walks towards you while pulling down her pants.
"It's only our third date you know. He will be taking me for a long walk on the beach. kind of clishé if you ask me, but hey it's a date."
You get no time to resond to her. As soon as she had finished her sentance she plants her face on your face as she has done so many times before.
"Who knows I might even get lucky."
With that she unleaches her morning pee into your mouth. Much more acidic and flavourfull than her evening pee. As she pees she lets go of a fart, as your nose is positioned right next to her anus you get to experience it all. After finishing peeing you can feel her anus doing some contractions.
"hmm, I think there is a number 2 in here aswell." she says
Alice shuffles forward a bit, aligning her anus with your mouth as she arches forward and increeing the pressure on your thighs your eyes are uncovered. You can see up her back and under her pyjama shirt seeing she does not have a bra on her.
Deep in your own thoughts you feel a warningshot from Alice as she lets go of a powerfull fart into your mouth. Her personal entré so to say. Not long after you feel her anus widen and a hot log exits and touches your toungue. She pushes all she got until she gets no further so she cuts it off; causing it to fall down into your throat where you process it to your delight.
"Ugh, this might be a while." Alice says and pulls up her phone and starts scrolling. You can feel her trying above you but to no avail. You hear her scrolling through short form video above you in five second snippets each. After a while you hear her laugh and tells you to look as she passes her phone behind her back presenting it to your eyes. It was a funny cat video that you found funny.
You start to chuckle a bit causing Alice to wobble a bit. She pushes her foot to the ground to regain balance. "Worth it." she says. Sibling rivalery and teasing still exists even if you serve as her toilet right now. Alice finally manages to get the last bit of poop out of her and instructs you to clean her asshole.
She then stands up and exclaims she needs to take a shower and starts to undress infront of you. All you can do is sit back and watch. There is nothing weird about taking a shower next to your toilet right? She even hands you her clothes to put in the hamper. Alice then steps into the shower and starts showering. Nothing really exiting happens, she just rinses off her body and hair.
When finished she steps out of the shower, reaches for her towel and starts to dry off.
"Alright jeff, i am heading out for my date and be back in a couple of hours ok? See you then"