the answer to your question fubar is that 1 of the persons knows "funny" better then the other person...if someone does something stupid and it is funny or anywhere near funny i do not tell them they are stupid...however 1 of the persons may think they know "funny" better then the other person when in fact the other person is wrong....
there are different kinds of funnny...
there is the "witty humor" which i have almost perfected...when sometrys to outwit me I laugh at thir stupidity because I know i am king of witts..however there are people of equal wittyness of me and i have to be cautious not to try to outwit them for it is impossable..one of equal wittyness cannot outwit another of the same...
Then their is "physical funny"...
this involves the jack butts and the Prank TV shows... where they beat each other up and fall of bikes and stuff...I have tried this "funny" but I have failed..There are many people that try this "funny" and i think this is the kind you are referring too..with this funny it is just own opinion..if you think what the person does is funny then respond with a laugh..if not then you either don't respond at all or call him stupid..
Stupid is defined as: given to unintelligent decisions or acts : acting in an unintelligent or careless manner
so techically if the person trys "physical funny" and you do not find it humerous you have the right to call them stupid...
there is also "tard funny" and "try to hard funny"
they are boring and do not last long but very very funny...
examples would be American Idol, alot of amatur stand up comedy and about half the people on this BBS
so there is your answer from my perspective....
megadud