The perplexing conjunction of pleasure and pain is, most precisely, the point at which Astrophil and Stella begins, the opening lines of the inaugural sonnet marking it out, quite explicitly, as the first in a series of clearly delineated steps:

Before she has read a word, then, Stella is somehow to have apprehended Astrophil's ‘paine’ – viewed it, perhaps, in what Thomas Nashe (one of Sidney's earliest and most percipient readers) was to call ‘this Theater of pleasure’ – as if an opening scenario in which ‘the deare She’ were set up as sadistic witness to Astrophil's carefully staged masochistic production were, in fact, not so much the first step in the programme he sets out as the very condition of its possibility. There is, presumably, something pleasurable about that experience – whatever it is – because we know from later sonnets that Stella does indeed go ahead and take step one and possibly two (reading and knowing of Astrophil's pain), even if she declines to go any further.