I guess it has to do with the relationship you share with the person. Probably it is the comfort factor - you're not worried about being judged. And by the way if you're judging me at this point and thinking that these funny friends of mine probably are not funny themselves, implying my bonhomie with them, then you're
I envy people who have the magical ability of bringing laughter wherever they go. It's their wit, their personality and the things they do, that make people smile/laugh/roll on the floor. On the other hand, you need people like me to giggle and laugh when the joke is out (that is if I get the joke, kidding). But really, either you have it or you dont. And forcing a bad joke down somebody's throat will only make you fall flat and lose all those teeth. And after you've visited the dentist to get them fixed, guess who'll be having the last laugh?