Yeah, it's hard to talk about Swinburne without mentioning "flower-sweet fingers, good to bruise or bite" or "pain made perfect in thy lips/ for my sake when I hurt thee." Apparently he was into that sort of thing. What's interesting about it is that he talks about it so explicitly in the 1860's. Other poets like Tennyson and Rossetti often would eroticize their subjects, but I can't think of anyone being so outright about sexual gratification in the polite literary magazines of the time. And this was coffee table material for many people. You'd have your political journals out, maybe a fashionable novel, and then a poem about someone biting their partner to get off. Many critics think that this makes Swinburne pioneering and original. They see him as breaking down Victorian barriers to sex, and perhaps promoting a more modern attitude toward intercourse, fetishes, and lesbianism. In The Times, Jonathan Bate recently suggested that "It could quite reasonably be argued that Swinburne was not merely the prophet of the twentieth-century sexual revolution but the person who first gave open voice in the English language to the joys of lesbianism." The appraisal of Swinburne in its entirety is rather lukewarm (http://entertainment.timesonline.co....cle6665787.ece), but there's a distinct appreciation for Swinburne's explicitness.
Yet I tend to think this view is based on a simple-minded understanding of the nineteenth-century. It presupposes that the there was only one conversation going on about sex--the restrictive, middle-class one that the twenty-first century is so antiquated with--but there were actually many different conversations going on about sex at the time. The way sexuality was approached in novels, for example, was quite different from the way it was rendered in the visual arts and poetry. Painting and verse appealed to a different audience and had different rules than those that applied to the novel. This means that where Thomas Hardy has to gloss over in Tess and Jude the Obscure, Swinburne could embellish. I don't think that what Swinburne was doing was really as transgressive as some people like to make it out to be. As I pointed out before, Tennyson and Rossetti's work had very erotic undertones. Rossetti even writes about orgasm. The difference between Swinburne and Rossetti is merely one of degree. They talk about similar things, but Swinburne goes a little farther. That makes him perhaps the most extreme, but it doesn't put him in a different category.
Anyway, you're right that he had a some kinky interests. What do you make of them? Do you think it helped or hurt his poetry?

