Sneak Peeking 

The act of checking out a girl without her noticing.

Bro there was this super hot chick I saw earlier, I was sneak peeking her.

Sneak Peeking by Big Scoop July 29, 2016

sneaky nut 

The act of pulling one testicle above your shorts and putting it back once noticed.

When was your last sneaky nut.

sneaky nut by ClemDawg227 October 2, 2016

Sneaky Beaver 

When a woman dresses like a man to hide her actually being a woman to avoid detection or get something for herself.

Stacy: Oh? Look at him, he's pretty cute. Think he'll buy us all drinks?
Linda: Don't bother. He's a Sneaky Beaver who comes in now and then to get drinks and leave without being hit on.

Sneaky Beaver by Sabercaster December 9, 2016

sneaky kneeler 

Sexual position in which an individual who is providing oral sex, surprisingly sticks a finger into the anus of recipient.

Bro, Janice gave me a sneaky kneeler last night. I kind of liked it!

sneaky kneeler by Runningforpresident January 2, 2017

sneaker wave

A random wave at the beach, most commonly on the U.S. Northern Pacific Coast, that comes to shore much farther and higher than any of the other recent waves. They aren't noticeable beforehand from shore and "sneak" up on people unexpectedly, many times causing people to be pushed over, or even swept out to sea.

The sneaker wave at Thor's Well, Cape Perpetua, Oregon, was deadly as it swept to sea the unsuspecting photographer who had chosen to ignore the signs warning of impending danger.

sneaker wave by memanelson February 3, 2017

Sneaky 

Making a typo in a text on purpose just to correct yourself and make it double text with no weird points

"Bro, I was sneaky so many times last night that Becky found out what I was doing"

Sneaky by GonzoPower February 6, 2017

sneaky asshole 

Fuckboys.

The sneaky asshole was flirting other females while in a relationship & even deletes text messages so he doesn't get caught .

sneaky asshole by Sneaky asshole , sneaky scum March 20, 2017