Weak in the knees 

Being weak in the knees means whenever you see something attractive or after you have sex and/or cum your legs feel weak

Hey do you see that hot girl over there?!

Yeah look at her fat ass

Man she’s got me weak in the knees

Weak in the knees by Billybobjr69 November 6, 2018

grandma knees 

Resulting from consuming large amounts of alcohol or smoking too much weed, grandma knees occur when a person begins to lose their balance and begin to cripple at the knees. This phenomenon is similar to knee struggles that elderly women have.

guy #1: How the fuck did you walk home last night you shotgunned two four lokos before you left the party?
guy #2: Trying to walk home was hell, I had a terrible case of grandma knees.

grandma knees by yTwigg June 30, 2016

packet knees 

When you have had to much packet and your legs stop working

Pass me my drink i cant move my legs ive got packet knees

packet knees by Lewdoo December 4, 2016

war knees 

War Knees is when ones knees are completely fucked up as a result of shooting at ISIS during this crazy shit war.

"SORRY MAN, I CAN'T PLAY FOOTBALL WITH Y'ALL...I HAVE WAR KNEES."

war knees by WarKnees April 23, 2017

crunchy knees

Whenever you get up and your knees crackle because you're getting old. Also known as bubbleguts syndrome.

When I got up from the floor I had crunchy knees.

crunchy knees by buttsbot November 29, 2018

The fleas have reached my knees 

When you believe your old enough that you froth girls in a sexual way

“Boys gather round. The fleas have reached my knees!”

The fleas have reached my knees by For Sure Dharmic April 20, 2019

sex knees 

1. the bruises on your knees from giving head.

2. the scraps and bruises on your knees from grinding in the "on top" position

girl: OW! look at my knees! they're bruised as hell.

boy: but weren't those sex knees so worth it?

sex knees by indubiately April 19, 2009