Fight Fire with Fire by duplicity

Chapter 1: Part One

The day his father brings home Lily Luna Potter, a girl who can't possibly be older than Tom is, Tom says nothing. He says nothing, goes to his room, and texts Barty about Tom Riddle Senior's latest mid-life crisis.

> does she have a dad? fight fire with fire lol

And, well, Barty means it as a joke, but it gets Tom thinking. So he looks her up. He looks up Lily Luna Potter on Instagram and Twitter and VSCO and TikTok, all the places that girls his age are hanging around on, and eventually comes across her father.

Her father isn't half bad, if Tom's being honest. He's actually rather handsome—defined square jaw and dark, thick hair. Jewel green eyes. Tom imagines, for a moment, fucking Harry Potter at his house, wherever that is, then having breakfast across from Lily Luna Potter the next morning.

The more Tom thinks about it, the more it sounds like fun.

So he thinks about it, and he definitely jerks off more than once to the idea of fucking his father's girlfriend's father in the bathroom during a wholesome 'meet-the-family' dinner.

Then, on Lily Luna's twenty-first birthday, Riddle Senior buys her a car, and Tom decides enough is fucking enough. He's sick of hearing about this ginger-haired angel who can apparently do no wrong. He thinks it's time to give his dear old dad a taste of his own medicine.

By now, Tom knows more about Lily Luna than he cares to, but this is information he can leverage. He knows where she lives, where she goes to school, and most importantly, where her father works. Her single, divorced father.

Harry Potter works as a gym teacher, which Tom doesn't think much about until his stalking leads him to trailing Harry at the gym. Even for a man in his late thirties, Harry is fit. Tom wonders idly after the man's ex—the high school sweetheart that birthed Riddle Senior's latest plaything—before writing her off as tasteless and unimportant.

The plan is to seduce Harry Potter, frighten away the prepubescent girl that Tom refuses to ever call stepmother, then rub his father's face in it. If he's lucky, he'll even get an excellent lay out of all this.

Now, Tom can pass for older or younger if he likes, but on the whole, his past hookups have preferred him clean-shaven—so younger it is, or at least, not older, which would defeat the purpose anyway.

So Tom goes to the gym without changing anything, counting on his good looks and natural charisma to get him what he wants.

He does not get what he wants.

In fact, Harry laughs at his carefully calculated proposition. Not in a cruel way, but humiliation burns in Tom's chest nonetheless.

"You're very sweet," Harry says, smiling, "but I'm not interested." In response to Tom's blank expression, he adds, "If you'd like a workout buddy, then I'd be open to that? It's like pulling teeth to get my friend Ron in here more than once or twice a month."

Unwilling to admit failure, Tom purchases the gym's monthly membership on his father's black card and tries again.

And again.

And again.

"How old are you, even? Nineteen? Twenty?"

Tom, who has been so hellbent on pissing off his father that Harry is all he's thought of for nearly two entire weeks, explodes, snapping out an irate "I am twenty-five," that makes Harry's humouring smile curl even further with amusement.

"So young," Harry teases, mischief dancing in his eyes. "I have a daughter a few years younger than you, you know."

Tom wants to say yes, he does know, he knows very well, but that would be counterproductive to his goals.