Problem with ID
My sisters boyfriend bought an apple iphone 5 and had his apple ID on it, then he gave that phone to my sister and she logged with her apple ID and after that his apple ID got blocked (at that moment he had iphone 6). It was 2yrs ago. So now my sister gave me her iphone 5, and Im scared to log in wih my apple ID so hers dont get blocked as it happened to her boyfriend? What should I do? Thanks