Not at all Jerry. A good humorous song, IMHO, will stay on the same tack/subject throughout (the 5-6 verses I mentioned), and not deviate off into other unrelated subjects just for the sake of another totally unrelated joke. But there will be a good laugh in each verse, but save the biggest one for the last verse. A good, simple, easily learned chorus helps too. That's my formula if I'm songwriting.