my stepsister does the laundry and I seduce her to have sex before stepfather arrives

Today I went out shopping at the supermarket, it took me about 30 minutes, then I got home and found that my stepsister was doing the laundry, I asked her if I could wash my clothes and she said yes, I also asked her if my stepfather at home and told me that he had left the house and that it was going to take a while to arrive, after that he asked me for my pants and my shirt, I only stayed in my underwear and I told him that we should have sex with clothes and I started to push my penis into him on her buttocks, after this she was very horny and wanted to start real sex