answer:Do the interview, but keep in mind a ‘bird in the hand, is worth two in the bush’. If you’re going to jump ship, now is better than after you’ve started and been trained. Sometimes this happens. In my experience, the university will go to their next preferred person and give them the job if you turn them down now. If this second job is your dream job, I don’t think you can not try for it. You’ll spend a long time wondering, ‘what if’. So give it a go and see what happens. You might not get the second job! Then again… you might!