The associations of the word pain are mostly strongly negative; it’s the opposite of pleasure, and pain is normally to be avoided. But there are contexts in which pain is embraced, for its psychological values — as in BDSM practices. For instance, in man-man sex, as noted in an AZBlogX posting of mine (of 2/25/13) on “Fetish/kink porn”:
An overarching theme [as in the gay porn flick Hoodies] is Taking It: experiencing, and enjoying, pain, humiliation, and abuse … An exhibition of parodoxical masculinity, showing how much of a man you are by showing how much you can take from other men. But also Submission, an abandonment of will to another man, recognizing him as superior to you.
Pain, suitably limited, also stimulates the release of hormones that can be experienced as intense pleasure. In addition, the Way of Pain in BDSM is highly ritualized, designed to work for both participants, which opens BDSM to being understood as a kind of ceremony or therapy.
That brings me to Leo Forte (treated in an 7/28/13 AZBlogX posting here), a star on the gay BDSM circuit who sometimes bills himself as “The Prince of Pain”, because of his appetite for torment (and other forms of kink).