Comedians love to test an audience by pushing the envelope. Push hard and, if you get a good laugh, push even harder. Keep pushing as you test the crowd to see how far you can go without completely alienating people.
Gavin McInnes's memoir How To Piss in Public is one that I highly recommend. It's not only insanely hilarious in a mental hospital sort of way but it's also so outlandishly offensive that you get tricked into thinking it is totally politically correct.