Thus it came to be, that one fateful day, tiring of Mary Jane Watson, Peter Parker searched for a woman of his own kind to mate with. He found Jessica Drew, the Spider-Woman. And together they mated...When it was done, Peter left. Going back to his mundane life with MJ. And Jessica was left alone, eventually, Jessica learned that she was pregnant. She decided to keep it, and because of both her and Peter's radioactive hybridity, she gave birth within one month to a baby... who rapidly grew to manhood.
She called him....
Meanwhile, 
What followed was a fight for supremacy. Scarlet Spider was technically already a teenager (by spider terms), with the corresponding teenage sexual hormones. 
And 
So they fought!And what a battle it was! And as these stalwart men fought each other, they felt an unnatural heat stirring in each others loins. They looked at each other, and despite their status as father and son.... 
They gave in to their desires. Each one claiming the other in every manner possible. However, as they lay sleeping in each other's arms, THE SCARLET SPIDER took advantage of the situation... 
He tied his father up in his natural webbing. And pried the mask off, wanting to see his father's real face. He was surprised to find that the man he just had sex with was.... 
Imagine the Scarlet Spider's horror when the man in the Spider suit told him, COME TO PAPA, BOY! READY FOR ROUND TWO ARE YA? 