He should have been mine.

That had been the thought that filled Severus Snape's mind up to the brim with loathing in the first place.  Had that pompous, arrogant Potter not turned Lily's loyalties away from him, he would have been the father of the little boy whose picture was featured in the paper last week.  He had loved Lily with all of his heart, but one little slip of the tongue later, he found himself watching her clinging to Potter as if he was some sort of righteous gentleman instead of the asinine hellion that he was.

Oh, how Severus loathed him.  James had taken Lily right out of his firm clutch-Lily, who had been everything to him.  They had at one time been knit together so tightly, but when they had frayed, she never once looked back from the path she had chosen. 

Somehow, Severus had managed to deal with all of that.  The baby, however, was an entirely different matter.  A baby signified love and happiness, both of which were things that Severus didn't have.  It was cruel-how dare Lily and James find happiness when he, Severus Snape, had suffered his entire life drowning in misery and despair!  It wasn't fair!

With that in mind, Severus had done the one thing that every Slytherin in his position did...

Take revenge.

Oh, it had been so easy too.  One sip of polyjuice potion was all it took to sneak into the maternity ward of St. Mungos unnoticed.  Then, after telling the head nurse that the proud parents wanted to see their son, he had slipped into the shadows and disappeared from the public eye.

With a flood of cunningness, Severus had soon enough found himself slamming the door to his house while a thousand morbid thoughts sifted through his mind like grains of sand.  He would kill this newborn and rid the Potters of their undeserved happiness!  It was time that they suffered for a change!

Wanting to feel the satisfaction of completed revenge, Severus had only taken a second to lock the door before he placed the babe on the counter of his laboratory and prepared to twist the boy's little neck around until it broke with a satisfying crack.  His hands had been bracing the boy's tiny body, ready to put the sleeping boy out of his misery, when the inevitable had happened.

Harry opened his eyes.  Green eyes, just like his mother's in shape and hue.  Though they were sleep-filled and lazy, he saw that they sparkled too, just like Lily's when she was joyous.

Merlin, he had then thought to himself.  I'm a monster.

And indeed, he was.  He had been about to kill a baby, for pity's sake; a helpless little baby.  It had all been an act of revenge too.  However, revenge wasn't really what Severus wanted at all-not against Lily, the only person during his entire lifetime that had treated him half decently.  He could not do it.  He simply could not...

...which explained why he was standing on the Potter's doorstep in the middle of the night, cradling a tiny being in his arms.  A being created from a love which he would never experience.

Blindingly intense rage filled Severus' mind due to his sudden lack of will in fulfilling his revenge.  He wanted to experience the love and happiness that Lily and James had!  He wanted someone to touch him willingly and smile at him and enjoy being in his presence!  Why couldn't he just once have that experience?!

All at once, Severus' mind filled with all sorts of malicious thoughts as he stood there, his glare intensifying with every second that passed. 

He should have been mine!

I loved her...but it wasn't enough.

It never would have been enough. 

Therefore, she owed him...

...and Severus would take what was rightfully his.

Suddenly, Severus Snape found himself with a son.