show me your shower head

Is code to ask a male to show his genitals, particularly his penis

Hey dude wanna show me your shower head? No! I'm not showing you my pens! Stop texting me!

Don’t Let It Go To Your Head

Now that you know
How I feel about you
Don't let it go your head, no
Don't let it go to your head, no no no no
Now that you know I can't live without you
Don't let it go to your head, no
Don't let it go to your head, no no no no
Don't take advantage of my love
Treat me good
Treat me bad
Treat me bad
Now that I'm givin' you every part of me
Don't let go to your head, no
Don't let it go to your head, no no no no
'Cause if you're playing games
It would be a shame
Don't break my heart
Don't break my heart

Now that you know how I feel about you
Don’t Let It Go To Your Head, no
Don't let it go to your head, no no no no
'Cause if you're playing games
It would be a shame
Don't break my heart
Don't break my heart
Don't let it
Don't let it
Don't let it
Go
To your head, no no no no

put your head out of the stand!

Please start to pay attention to the surrounding around you!

I think you are gonna have to put your head out of the stand!—Fantastic Beasts: The Crimes of Grindelwald (2018)

do you gaze at your bald head and wish you had hair

The arranged version of the song's lyric, by Elvis Aaron Presley(known as Elvis Presley). He performed the song called "Are You Lonesome To-Night?" in August 1969 at International Hotel in Las Vegas. The original lyric is "Do you gaze at your doorstep and picture me there", however he was in high mood, he apparently changed it to "Do you gaze at your bald head and wish you had hair". A moment later, Elvis noticed that a bald man in the front row took off his wig and swaying to the music.

Are you lonesome tonight,
Do you miss me tonight?
Are you sorry we drifted apart?
Does your memory stray to a brighter sunny day
When I kissed you and called you sweetheart?
Do the chairs in your parlor seem empty and bare?
Do you gaze at your bald head and wish you had hair?
Is your heart filled with pain, shall I come back again?
Tell me dear, are you lonesome tonight?

Little-Person-In-The-Back-Of-Your-Head-Syndrome

When there is a little person in the back of your head that keeps making you worry about things. This is not meant to be some sort of mental condition and is instead a concept. A way of personifying your anxieties into a sort of anxiety demon. This is incredibly useful as it allows you to tell said personified anxieties, to fuck off. The acronym of this is LPITBOYHS which fits perfectly as we want all of our anxiety demons to go into a pit, from which they will never return.

I use Little-Person-In-The-Back-Of-Your-Head-Syndrome. My anxiety demon is named Kevin and I fucking hate him.

On your dummy head

A term used when your are dealing with incompetent people.

Also when you get a kill or block in volleyball

Julie said “on your dummy head” when she got a kill and won the game.

Don't wreck your head over it

Don't overthink it. Don't be petty.

If someone has been nagging you about the same thing over and over like...

"You already have 6 different types of flour, why don't you use the ones you have before buying another one?"

Short answer, "Don't wreck your head over it".