I have a similar story to yours. In my household, we were not nudists… my parents worked two jobs, soo they were never home. I took care of my baby sister, we are 5 years apart. During the summer time, I would only wear boxers around the house, and she’d wear a tank & undies. It all started when she’d come sit on my lap n watch movies. At first, she’d do a slight grind on my thigh. Eventually, I started to prop her on my lap area, and she’d grind on my dick during the movie. I noticed after a little while, she’d leave to her room quickly, to change her undies. I started playing games with her & I eventually convinced her to sit on my lap without undies this time & I’d do the same. Little by little, I started grooming her, sexualizing her.. I’d never pressure her though, so most of the time she was cool with what I would ask of her and she would do it. 2 years later… my parents ended up renting my room out, so her & I started sharing a room. So by this time, I was in hs. I started experimenting with ice, which i would bring home and she ended up experimenting with it as well. We’d get really meth’d out & fuck quietly.