First the laughter...
...then the inevitable "well, actually..." beard-stroking. Because I'm less interested in whether or not David Cameron did actually have sex with the mouth of a dead pig than I am about why the pig was dead in the first place. Isn't it arguable that once you kill a pig for the purpose of eating it, also using it for alternative pleasures is actually a net positive? I mean, it's transparently obvious that no-one at the event needed to kill a pig in order to live; they'd have no difficulty switching to a vegetarian diet. That pig, in other words, had already died for the sake of people's enjoyment. I'm not sure how much business I have sneering or even giggling at people who want to get two very different forms of pleasure from something I only enjoy in one way.
Put another way, "Man who has pigs killed for his own pleasure disgusted at man who has pigs killed for those pleasures AND others" doesn't strike me as the sturdiest of platforms from which to spit at someone, even someone who so desperately needs to be spat upon at all times by all people. I'm not saying no-one can express moral outrage at this, only that I can't be one of them. I'm too compromised.
Of course, I can still find it uproariously funny, at least until it's revealed that Cameron has been struggling for years to keep his bestiality tendencies under control. At that point, I might even feel sorry for the guy.
I can't promise anything, though.