Babysitting my two younger siblings

A story where a mother and father trust their oldest child to watch their 1.5yr girl who's being potty trained and their 1yr boy who's just not ready yet to be potty trained but is always interrupting his sister when she's on the potty by taking all his clothes off leaning over the front of her potty while she's still going potty and peeing on her toddler sized vagina.  Jack and Jen their kids Jack Jr the oldest their 1.5 yr old Sammy, and the 1yr old Nick who's only 5 months younger than Sammy.  Jack and Jen leave the house for date night. They leave Jack Jr in charge and tell Sammy that big girls don't just learn and use the potty but they also help their parents or older siblings with the youngest sibling.  In this cars Sammy has to help Jack Jr with her little brother Nick. This means with the diaper changes baths and feedings for Nick.  Sammy been a real good helper for her parents and older brother and a good big sister to her baby brother.  She changes Nick's diaper but sometimes her brother or parents have to help her with it.  So Sammy been real good at helping and using the potty, but as her second birthday gets closer and closer. she starts thinking why do I have to use the potty when my brother who's only 5 months younger still uses his diaper.  So the one day Jack Jr goes to check up on Nick and Sammy. He finds Sammy not wearing her training pants but instead one of Nicks fresh diapers while she is changing Nick's wet diaper.  Sammy why are you wearing one of your little brother's diaper, because why does Nick get to wear them and go potty in them.  Sammy it's because he's just as older as you were before we started potty training you.  While Sammy and Jack Jr are talking about why Nick's allowed to wear and use diapers and she's not allowed to, Nick starts peeing on Sammy.  Eww Jack Jr Nick's peeing on me and I don't like having pre on me.  See Sammy you just proved why we started potty training you. I did how because Sammy you said that you don't like any pee on you. Ok so what's the big deal if I pee in this diaper I have on, well Sammy you would have pee on your body wouldn't you. Um yes I guess so but how does the potty help me. The potty helps you Sammy by giving your pee something else to be on instead of your body. O ok Jack Jr wait aren’t we're forgetting about Nick, how are we going to keep the rest of his pee from getting on me. I know how Sammy but you have to do what I tell ok Jack Jr. Sammy first pull the diaper over his penis, second put one hand underneath the front of his diaper and grab his penis. What's next Jack Jr now Sammy rest your chin on the front of his diaper, open your mouth and pull the front of the diaper out from underneath your chin. Now I'll help you Sammy aim his penis so his pee will go in your mouth and nowhere else. Eww Jack Jr why couldn't I just have left the front of the diaper over his penis, I would've just stopped you there but this step is part of your punishment for wearing one of his diapers.  O ok Jack Jr I'll do it but only because it's my punishment for wearing a diaper, but Jack Jr yes Sammy where did you get the idea for me to drink his pee. Sammy I got the idea from the one time I was watching you before our baby brother was born.  Ok Jack Jr but you only told when you first got the idea and not why you got that idea, because the one day I was watching you mom and dad said not to let you have to much to drink before I change your diaper.  Ok so Jack Jr yes Sammy did you accidentally let me drink to much liquids before you changed me that one day, yes. You started peeing while I was changing you and I didn't have time to cover your vagina, so I opened my mouth and let you pee in it until you were done then I waited a few more minutes just to make sure before putting a new diaper on you.  You know what Jack Jr Nick's penis feels godfathers in my mouth but now I want more.  Like what Sammy i want it in my toddler vagina, um Sammy I don't think we can put his penis in your vagina. Why not I was able to put in my mouth, um yes but penises have to be erected if you're going to put them in a vagina. Hey Jack Jr i found these maybe they can help, um Sammy we shouldn't drug our little brother I know Jack Jr but mom and dad are out of town.  So what's that supposed to mean Sammy, it means that they won't come to find baby Nick with an erection and his penis in my vagina. That's true but just for tonight we'll drug him so we can make his penis erect.  O and Jack Jr isn't his birthday just 5 months away yes it is, so how about we all play in my room after we're done making our baby brother hump me.  Sure sis and hey if his erection goes completely soft after I'm done shoving his penis in and out of my toddler vagina we can start working on potty training him. Ok Sammy so if it does I'll help stand him up so he can pee standing up in the potty, but what if doesn't then I sit down on my potty and you lean his erected penis so it hits my toddler vagina when starts peeing in the potty.