Since this is a question about the sex lives of Sultans, did any of them ever have any male slaves for sex, or was it 100% female slaves? If so, how was it seen?

Although this does not pertain to all sultans generally, the sexual proclivities of Ibrahim the Mad (and certainly others) have been noted. The influence of the Sultan in the actual affairs of the Empire waned and waxed through the lifetime of the lifetime of the Empire, there were indeed times when the Grand Vizier held sway over the major decisions whilst the Sultans explored their sexual interests, of which the Harem played a very focal point.

...Earlier in the Seventeenth Century, it has been the Grand Viziers who had saved the Empire while the Sultans sat in their Harems indulging in their tastes and fantasies...As all the women in the harem were totally dependent on how well the sultan was pleased, all were eager for opportunities to reach his bed and once in it, desperate to please. So much so that several Sultans, surfeited with endless days and nights of passion supplied by platoons of eager, adoring women, went, quite simply insane

An amusing example of this is the aforementioned Ibrahim the Mad. From the same source:

Deciding that the bigger the woman was, the more enjoyable she would be, he [Ibrahim the Mad] had his agents search the Empire for the fattest woman they could find. They brought him an enormous Armenian woman, who so fascinated the Sultan that he heaped riches and honours upon her and finally made her Governor General of Damascus

Source: Massie K.R. (2013) Peter the Great His Life and Work pages 536, 651. Head of Zeus, London