Newbie - A novice hobbyist or novice provider.
NGO - Non-Government Organization
NGP - Non Genuine Photos
Nooner - A lunch-time or afternoon session, popular with married hobbyists.
No-Show - Escort or Client never shows up for an appointment, does not contact in advance to cancel or warn.
No-Touch - No touching allowed. (e.g. No-touch Jack shack, no-touch strip club)
NQBC - Non-quitter, but covered. CBJ to completion.
NQBS - Non-quitter, but spitter. BBBJTC and spits your ejaculate.
NQNS - Non-quitter, non-spitter. BBBJTC and swallows your ejaculate.
NSA - No Strings Attached.