Really Want That Job? Don’t Make These Six Mistakes. Mistake #5: Taking a Casual Interview Environment Too Far
The interviewer is not your friend and shouldn’t be treated as such. The best interviewers have a way of making you relaxed and comfortable, but be careful not to get relaxed to the point where you’re talking in a manner and tone that’s unprofessional. No matter how casual the environment, or how much rapport you have with the interviewer, keep it businesslike.
The Fix: Always remember that an interview is a business meeting, and don’t do or say anything that you wouldn’t in that context. Simple, right?