I've got a start on

Melody: 

I'm Looking Over a Four Leaf Clover

Lyrics: 

I've got a start on a twelve-inch hard on
That I've had all afternoon.
Went to the doctor, he told me to cough
I wish that he would have whacked it right off!
Come to me, Venus, massage my penis,
And shrivel it like a prune,
Cause I've got a start on a twelve-inch hard on
I'll probably have till June