Presumably, any job searching has been done in your own time. Since when is it your boss' business what you do outside of work? How's that different from a boss asking a married person "are you planning to file for divorce?"

What you do outside of work hours is none of your boss' business. I think you should decline to answer.

> I'm not really sure that's an appropriate question and I respectfully decline to answer. Any and all activities I may or may not engage in outside of business hours are part of my private life and I wish for them to remain that way. Thank you for understanding.

How's that different from you asking your boss: "are you planning to lay me off or fire me?" or being asked about your religion during an interview?

I've been in places where management constantly talks abot how employees are their "greatest asset" only to lay them off in large numbers a short time later..