"Oechan, just a little bit of it, so I'd like to put it in..." My sister who became a school student even though she has a narrow bath still wants to enter with me!

My sister who still wants to take a bath with me is already a student. My sister's chest and buttocks are too narrow to enter together, so I can't stand it! Moreover, if you think that it is bad to get up with your sister, my sister is interested in a wake-up ○ Po! i want to be able to insert it, so my reason is limited... i'm incest.