An acronym for "Not safe for work if you work in a really strict place".
NSFW refers to things that would clearly get people in trouble for viewing at work - like naked people. So nsfwiywiarsp is for things that may of may not be okay depending on the strictness of your workplace.
"Strict" may also be replaced with Stodgy, Stuffy, Stupid, Snotty, Shitty or Slack.
NSFWIYWIARSP Below! Jusin Beiber in nothing but diapers!