Edit: assuming this friend does not live anywhere near you/anything in-person is out.
A while ago while walking to the train I ran into one of my roommates (who I get along best with) on the street. He asked if anyone had asked about/for him and I said no. He then asked that, if anyone did ask for him, that I tell them he doesn't live here/I do not know who he is. I said ok and didn't ask more because I was in a rush/not my business but...for kicks and giggles, why do you think he asked such a thing of me? non srs answers preferred xP