The denial of any distinction between foreseen and intended consequences, as far as responsibility is concerned, was not made by Sidgwick in developi… - G. E. M. Anscombe

There is no such thing as a casual, non-significant sexual act; everyone knows this. Contrast sex with eating - you're strolling along a lane, you see a mushroom on a bank as you pass by, you know about mushrooms, you pick it and you eat it quite casually - sex is never like that. That's why virtue in connection with eating is basically a matter only of the pattern of one's eating habits. But virtue in sex - chastity - is not only a matter of such a pattern, that is of its role in a pair of lives. A single sexual action can be bad even without regard to its context, its further intentions and its motives.

The trouble about the Christian standard of chastity is that it isn't and never has been generally lived by; not that it would be profitless if it were. Quite the contrary: it would be colossally productive of earthly happiness. All the same it is a virtue, not like temperance in eating and drinking, not like honesty about property, for these have a purely utilitarian justification. But it, like the respect for life, is a supra-utilitarian value, connected with the substance of life, and this is what comes out in the perception that the life of lust is one in which we dishonour our bodies. Implicitly, lasciviousness is over and over again treated as hateful, even by those who would dislike such an explicit judgment on it. Just listen, witness the scurrility when it's hinted at; disgust when it's portrayed as the stuff of life; shame when it's exposed, the leer of complicity when it's approved. You don't get these attitudes with everybody all of the time; but you do get them with everybody. (It's much too hard work to keep up the façade of the Playboy philosophy, according to which all this is just an unfortunate mistake, to be replaced by healthy-minded wholehearted praise of sexual fun.)

But we lay people are not less called to the Christian life, in which the critical question is: "Where does the compass-needle of your mind and will point?" This is tested above all by our reactions when it costs or threatens to cost something to be a Christian. One should be glad if it does, rather than complain! If we will not let it cost anything; if we succumb to the threat of "losing our life", then our religion is indistinguishable from pure worldliness.