Well, whenever you boys are having a bout with the temptation to engage in onanism - just think of the words in my avatar (too small to read in the pic), which are:
"Every time you masturbate, God kills a kitten ... so please
... think of the kittens!"
(Maybe that poster should be hung in every serious practitioner's bedroom
A public service message from Mt. Meru,
NB - On a more serious note - for a monk or nun - porn or onanism (I like that word better) is a no-no. As for a lay-person - I guess it depends. The best porn is really inside one's own head - imo - and as to onanism - well - stream enterers can enjoy sensual pleasures - it's the other 3 levels that abstain - no pun intended - but yes - truly abstain from all sensual lusts. I think there's a balance here for us 'regular' folk is my point - another pun comes to mind here but I will forbear.