NSFL

NSFL also known as NLS means Not Safe For Life or Not Life Safe normally referring to a link someone or some website has sent you meaning no one should ever see it.

www.2girls1cup.com is NSFL no one should ever see that

NSFL by Kelby Raper January 27, 2008

NSFL

Not Safe For Lunch. A warning that linked content is sufficiently horrendous as to be sensibly avoided by the weak of stomach.

This website|image _link_ is NSFL.

NSFL by Morosoph January 22, 2009

NSFLB 

Not Safe For Little Bros. Basically something you shouldn't watch when your little brother is in the room.

I was searching 2 girls 1 cup for the first time but I had to wait b/c its NSFLB.

NSFLB by DronerTheMegaBoss June 11, 2011