two faced

Have you ever had a friend that sometimes you wish you feel like killing the person and other times you think she's/he's the nicest person on earth ? I mean like firstly you start talking with the person and find out she's/he's very nice, then later she does something very annoying. And the thing most annoying thing about her/him is that when you want to start liking her/him as a friend she/he does something to annoy you? I mean why can't people like that have one character so you could be free to hate or like them. If you have a friend like that or know someone like that COMMENT