Dear Rabbi, I already have a job but there is an opportunity for another (perhaps better) job but I would have to take the interview during work hours. My boss is the type to ask me all sorts of questions especially if I request to leave early. I don’t want to lie to him but I know I will get in trouble if I tell him the truth. My sister is also pressing me to go to this interview because she feels it will better my position (maybe). We live together and extra money wouldn’t hurt our situation either although thank G-d we are not lacking anything presently. Please advise me on what to do as I do not want to upset anybody. Thank you in advance.

Don't lie, but find an opportunity that would enable you to do the interview without lying. An employeee is entitled to interview for another job without informing her current employer. Take, for example, a whole day off which you spend with your family and for one hour go to the interview. If asked - you decided to be with your family.