Unless he's a male witch and has some serious demon hunting to get on top of, then there's not really an excuse for constant family or friend related emergencies. When he's with you, he will give you his full attention and everything else will become irrelevant, even if it is for a couple of hours. If he keeps on getting mysterious phone calls that he has to leave for straight away, then he's using the whole 'this date is going terribly, ring me so I can escape' card. Or he has a wife and three children... If you know any other sure signs that a guy is into you apart from him directly saying "hey, I'm into you' then write them in the thread below.