About once every six months there is a breakthrough on the male contraceptive pill. Everyone gets excited for about five minutes, then realizes it's an appalling notion. Here's a reminder why.
History is littered with incidents that prove Kingsley Amis's theory that male libido is like being "chained to an idiot." Otherwise sensible men will do incredibly stupid things when that idiot decides it wants something. Ask Bill Clinton, or David Letterman or just about anyone with a penis. The same quantity of men would lie about being on the pill as do about about pulling out. The same quantity of women would be somewhat upset about this.
Even if men changed overnight, and became paragons of honesty and virtue (that women probably wouldn't want, because they'd be too sissy) no-one would believe them when they told the truth. They'd be the gender that cried wolf.
Even if this fundamental issue was somehow bypassed, through some kind of truth and reconciliation commission, men would forget to take the pill in the same numbers that they forget to buy condoms.
Talking of which, sexually transmitted infections and diseases would probably spread a bit faster. Don't think that's plausible? Four words: male pill, Jersey Shore.
Finally, if all that were overcome, imagine the column inches and hours of talk radio and TV that would be dedicated to real-life male pill stories. Just think of the terrible headlines. So put your fancy hormone down, and step away from the centrifuge, scientists.