If you have decided on another offer, it's not rude to be honest and explain why you have chosen another position. Focus on how the other offer is a better fit

If you have decided on another offer, it's not rude to be honest and explain why you have chosen another position. Focus on how the other offer is a better fit for you. If you have decided you just don't like the company or the position, continue with the interview just to hone your interview skills and to be professional. But keep your answers succinct and don't fain enthusiasm. A seasoned manager will get the message and will cut the interview short.