Don't you ever knock 你进来之前不会先敲门吗?
Where did you learn your manners? 你哪儿学来的规矩? Can't you be more friendly? 你不能更友善些吗?
Can't you be a little nicer? 你不能更客气些吗? Do you have to be so mean? 你非这么凶不可吗?
Must you be so cold 你非如此冷酷不行吗? He sure is cheeky! 他真傲慢!