I Write Lewd Parody Music in My Head
 

...and I'll bet you do, too. So, share it, already! It doesn't have to be a complete composition, but you should include enough lyrics to help us laugh out loud, and, of course, the song that you are using for the tune should be noted.

Let me throw out the first example. Sing this to the tune of "Jesus Loves Me" :

"Jesus loves me, more than you
I'm a Christian, you're a Jew.
Being Jewish breaks his heart
You heathen bastard, worthless fart."

I have more. You do too.

To the tune of "Strangers in the Night":

"Strangers in my shorts, there uninvited,
Strangers in my shorts, I fear I'm blighted"...

Add your own. Fun for the whole family. Young children are particularly good at this.

Put your gland in the hand of the man that stilled the waters...

I didn't make this one up, but I do enjoy:

Leprosy, bits keep dropping off of me
I'm only half the man I used to be
Since I contracted Leprosy

(To Yesterday)

LOL! I agree. Sometimes I also write horrible limericks in my head too. It's all true. Sometimes I write entire songs that are not parodies either..like:
"I Smell Like Gasoline"
and
Varieties of
"Parking Lot Hooker"
The lyrics and rhyming scheme change depending on my humour.
:)

From kid-time:

Strangers in the night, exchanging rubbers
This one is too tight, I'll try another...

Or the old cheer:

Be Aggressive, be be aggressive (then you spell)
B-e-a-g-g-r-e-s-s-i-v-e agressive be be agressive. (Wooo!)

Changed to:

Prophylactic, pro pro phylactic
P-r-o-p-h-y-l-a-c-t-i-c phylactic, pro pro phylactic (Wooo!)

[To the tune St. Thomas (Williams)]

I do not trust James Bond
I think he can un-der-stand
For ev'ry place he goes blows up
He is a dang'rous man.

I do not trust James Bond
And here's for the rea-son why
For ev'ry lady Ja-ames Bo-ond loves
Is sure-ly doomed to die.

My song must have its end
But in this world and be-yond
Of one thing I am absolutely sure
I do not trust James Bond!

coda: I do no-ot trust, I do no-ot trust, I do no-ot trust James Bond!

The wife came up with this one. Sometimes we collaborate; we really need to finalize all the verses of "The Great Loch Ness Monster" sometime before one or the other of us dies.

Instead of "You might as well face it, you're addicted to love", we would sing "You might as well face it, what your dick did to love".

And to 'King of Pain' by The Police:

There's a little black spot on the bathroom floor,
Same ole spot that was there before.

And to the tune of 'If your happy and you know it clap your hands', the classic:

Got a skeeter on my peter, knock it off
Got a skeeter on my peter, knock it off
Got a dozen on my cousin, can'tcha hear the bastards buzzin'
Got a skeeter on my peter, knock it off

If I were the only girl in the world,
and you were the only boy.
You would have to pay and pay,
or you would have no joy.

My housemate used to sing this dylan song:

Whoooee ride me hard
tomorrow's the day
my bride's gonna cum
ooh ohh we're gonna fuck
down in the easy chair

etc.

"Knock?" I never heard it any way but "whack."

Sailor's Hornpipe:

Tiddly winks, old bean
Have you ever seen a queen?
Have you ever seen a Salmon
up a dead sardine?

I've seen a tinker up a tailor
and a soldier up a sailor
But I've never seen a salmon
up a dead sardine

Salmon won't fit in those little cans!

Summer's Eve
Makes me feel fine
Flowin' through the channels of my vagine

(did I just type that out loud?)

And wasn't that Breeze, not Eve? Or am I just sticking in the artsy mud here?