It is a decidedly unpopular thing to say these days, but I'll say it anyway, echoing a conviction of William James: Much profit comes from avoiding sensory indulgence.
A much more difficult practice is to enter into it with cool detachment. Coitus reservatus, for example. But it is no more difficult than playing blindfold chess, which is not that difficult. One experiences the sensations attendant upon sexual intercourse while remaining indifferent to them: one regards them as mere sensations. (In my lexicon, coitus reservatus requires non-ejaculation, whereas coitus interruptus allows it, but outside the partner.)
Could one take it one step further and ejaculate with detachment? This is hard to imagine, but conceivable. After all, Arjuna in the Bhagavad Gita was enjoined by Lord Krishna to kill with detachment. Try to imagine looking a man in the eyes and then running him through with a sword, all the while preserving one's equanimity. If it is possible to kill with detachment, then it is possible to ejaculate with detachment.
What could it mean to ejaculate with detachment? One would experience the sensations attendant upon the outflow of seminal fluid while viewing them as mere sensations. One would not lose oneself in them as is normally the case, but hold them at mental arm's length, or, to change metaphor, peer at them from within the fastness of the inner citadel. One would remain unattached. Like the chess master who keeps the draw in hand, one would keep one's ataraxia in hand.
Am I talking nonsense?
Companion post: William James on Self-Denial