Painful pleasures or pleasurable pains?

The following is not for the weak hearted nor for the prude. Please bear this in mind as you nevertheless read on (with the first sentence having piqued your interest in lieu of warning you).

It is surprising that there is a thin line between pleasure and pain. Sometimes it is clear that something is painful, but most often I need to rephrase that realisation to "painful for so-and-so". Individual perceptions of pain and pleasure are discriminated by a very thin line, which, now, not-so-surprisingly has a good deal of broken points where both mix well into a heady concoction. Breath easy while you try to recollect the various times in your life when pain seemed so pleasurable. Many a virgin has confessed to this on her night of consummation, many a well shaved face has been party to this after a dab of cologne across their visage, a close few admit to the sense of relief when the sphincter stretches painfully in the morning after an entire night's inactivity, the careful tongue which pushes out the lower lip till the skin cracks and then eagerly runs over the chapped and bleeding lips, women who delivered handsome lads and lissome lasses admit to this as well (although they did not enjoy the earlier portions of the labor pangs, they seemed to have queerly liked it when it reached its zenith as the child’s head popped out) and what I have read at places about the sexual preferences of some where pain and pleasure are better not sieved out. I remember reading it on a Linux system (late one night when day and night don't make sense). I had decided to take a break from the computer and play around with the fortune commands (try $>fortune. There are various options that can be given to fortune depending on the installation). "fortune –o" was always the favourite amongst the bored! In one of them I remember reading a justification for bondage! Very interesting. It said that when the individual is at her/his peak and the muscles throughout the body tend to contract, the inability to do so (due to the bonds) heightens the pleasure immeasurably. At least it made me sit back and think (and I had planned on giving my brain a rest!) and I stopped hitting on the fortune commands. Another place where I was presented similar fare (though this time I was repulsed by what I saw) was in the General's Daughter (John Travolta and Madeline Stowe, I think). I remember the movie Anjali (Tamil and pretty old) where Revati begs the child to continue hitting her if that was the only means by which she (the kid) would touch her (Revati). Why did I think off all this? Last night I poured a few drops of medicine for my eyes and it stung badly, but it felt nice. Maybe, because I thought that the sting was proof that it was being effective, or the silly pride that my eyes can withstand such sharp pain. God knows. But it felt nice, and I settled in for a night's sleep filled with wonderful dreams (did you know that all our dreams are seen in colour? No, not technicolour). When a couple (not necessarily a married one) split, there is some point in time when either of them wish pain for the other so that they get a chance to be there to assuage the ravages of that pain. Wishing pain for another in order to realise pleasure for both? This is not to be likened to the emotions at play in a vindictive mind; a vindictive mind clearly wants pain for another, and might not be appeased even after that is meted out to the other. A woman finds great pleasure in knowing that her man still pines for her, while she might or not admit that she is privy to similar pangs of separation.
Would pain, then, be a decision, conscious or otherwise? So ask it of pleasure, too.