You're upstairs. This is an inappropriate greeting. I believe you only have one such friend. If there is more than one, I should doubt your way of making friends. This friend, even your boyfriend, shouldn't do this. You should warn him and let him know what he is doing! I am a man (it seems that boys feel a bit like act young, alas, old! ) think rationally and solve this problem! It doesn't seem difficult, quack!