Kids and politeness

I noticed that Adam ni sangat garang dengan maid. Kalau main yelah, dia suka-suka and gelak-gelak. Tapi kalau nak mintak something, dia akan panggil dengan suara yang boleh dengar the authority in it. Macam contoh kalau with me, dia nak mintak susu, he will say "Mommy, milk please" in his sweetest voice. Tapi, kalau dengan maid, "Chitah! Milk!" on top of his voice. Sounded very rude to me. Even if I asked him to say it nicer, he would only lower it a bit but still not nice enough.

Initially, I thought it was me. I don't think I sound like that when I call the maid but people say kids emulate your behaviour. When we went back to my hometown the other day, I noticed Adam used the same voice when he called out my mom's maid. So it must not be me! I did not talk much with my mom's maid and never raised my voice when I speak to her. Adam spoke politely to all other people except the maid.

What should I do now? Whenever I catch him talking to the maid in that voice of course I will get him to talk nicer but what if I am not around and later it became a habit. I don't want to be the mother who raise a rude son. Sigh~