My sister, who I was living with, broke up with her boyfriend and came back to her parents' house. She was getting changed, saying that her package would arrive tomorrow. I should have been used to it, but when I saw her again after a long time, she was plump and her breasts were bigger than before. She invited her childhood friend over to her house and was having fun moaning and showing me off, but now she's trying to seduce me. She started playing with my dick, saying, "You know what to do to make her feel good, right?"