[SwollenBellyEnvy]

Just because someone has the audacity to ask about private matters does not mean that they should get a response. I suggest turning it around back to them: "I think it's a strange (or too private or too personal, whatever fits the situation between you two) Why are you so curious about what I do on my computer?" Or respond humorously: "Oh, oh oh! The computer is my innermost, deep dark secret - something I keep private between me and cyberspace." Or quite simply: "Some things are private. This is one of them." Or: "You are curious about unnecessary matters."