Your friend has invited you to the disco next saturday but you can't go. ( сочинение)

Будет в форме диалога.
—Hello, Alex! I have free Saturday. We can go to the disco. I love it!
—Oh, sorry. I can`t go. I`ll stay with my little sister all the day.
—Why can`t your parents do this?
—They go for a work all day.
—Great! So, can I go to you? I`ll bye many pizza and chips!
—But what about my sister?
—We`ll sit with her! What problems? I have a free day, so I want to spend it with benefit (польза)! I would like to learn how to treat (обращаться) with little children!
—Oh, it would be nice! OK, I wait you on Saturday in my house!
—No problems! Goodbye!
—Goodbye!