There is something I have done 4 times with mistresses I have come to know very well and deeply respect. In the middle of the session I am ordered to masturbate and then made to eat my cum (which some Dommes really like) However the more important element is immediately after that I am restrained and subjected to harsh corporal without a safeword. And because of the orgasm my ability to enjoy it has been greatly reduced.

I do this essentially to give a special treat to Dommes who are genuinely sadistic and willing to admit it. I make it clear that they should not to expect to do it again so enjoy it to the fullest while they can.

However one time a Domme improvised and instead of ordering me to masturbate she attached a Venus 2000 and kept it on until my balls were drained. After the first forced orgasm that became unpleasant and got worse. Furthermore multiple orgasms makes you even less able to enjoy the ensuing CP than just one.