A mathematician called Fred
Was having some problems in bed
His floppy part was short of loves
So his wife took up knitting gloves.

He buried himself in Pythagoras
Until hearing of Viagra on a bus
He went shopping with gusto on the net
For his lusto need not be over yet.

They loved in Tescos and the Woods
Now Fred could always give the goods
At last their lives seemed just fine
And his wife sold the knitting twine.

But there's a side effect with *Viagra
Besides the one we know 
It causes high pressure in the bladder 
Which bursts out when you 'go'.

So for Fred now problem two began
When one day standing before the pan
Letting nature take its course
He shot backwards with great force.

At high speed he hit a wall
Causing a heavy rad to fall
It landed tap first in his crutch
And damaged his organ rather much.

Badly injured in intensive care
He had major surgery there,
He left with a void where once was meat
Which made his pills quite obsolete.

*allegedly