Blatantly not letting somebody do something or performing some sort of action by blurting out "NO WON'T LET YOU!". They may not even do the action, even requesting it be done is grounds for a NWLY.
Dexter: Will you fill my car with special?
Troll: NO.
Dexter: But WHY?
Troll: NO WON'T LET YOU!
by Boulevard Nights June 4, 2010
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