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?

On your own head be it!

Idiom

used to tell someone that they will have to take full responsibility for what they plan to do

I am telling you, don't get married to her, she is a control freak but if you do then, on your own head be it!

If you want to quit a high-paying job to chase after some fantasy of being a travel writer, then on your own head be it!

go stick your head in a hornet's nest

A less vulgar way to say "fuck off". I personally coined the phrase and used it once or twice on some motormouth who rubbed me the wrong way. Hornets are mean, six-legged bastards, even meaner than their cousins: the wasps.

Shemp: You couldn't let me do it. You had to gum up the works.

Larry: Ah, go stick your head in a hornet's nest.

on your head

when you dunk on someone or do any type of elite athletic maneuver at an elevation that they have not attained

I double tapped on your head in rocket league!