Harley Potter and her world famous twin

Hello ,Aunt Petunia

Harry got off the Hogwarts express after giving his winnings to the Weasley twins for starting their joke shop and for getting Ron a new set of dress robes.
He was feeling very happy until he remembered that he had to go back to the Durselys'.

He saw Harley making her way to Sirius who was dressed very handsome in black jacket over a mesh T shirt and ripped jeans .
Harry wished to go with them so bad,  but he knew he couldn't. Not right now anyway.
Sirius had asked Dumbledore and got rejected according to Harley.

But she had promised him that she wouldn't let him stay at Dursely's for all of summer. She swore that she will. And Harry trusted his sister.
But still he couldn't help but be jealous of her.

Harry stood there ,on platform 9&¾ awkwardly as everyone went to their parents. As Hermione hugged her dad,  as Ron helped his mother, as Harley ordered Sirius to take her trunk, Harry stood there with Hedwig's cage in one hand and dragging his trunk with the other.
Then his trunk started floating on its own towards Sirius and Harley. He dashed after it .

"What were you doing standing there looking like an idiot? " Sirius asked as he got close.
"Harry doesn't look like an idiot " Harley exclaimed, coming to Harry's defense before he could even start to open his mouth.
His lips twitched up, only to return to a deeper frown when he heard her next words : "He is an idiot. A humongous idiot "

Sirius laughed, but then he said "Probably true. They say twins share every characteristic "
"Sirius " Harley groaned. "I am your daughter, you should be taking my side here"

It was a warning, Harry realized. They were in public. And to public Harley was Harley Black, daughter of Sirius
Black and he - Harry- was not blood related to her.
Sirius understood her hint.

"Well if you want the privileges of being my daughter, you should perhaps consider calling me dad" Sirius said matter of factedly

"If you want the privilege of having a head over your neck , you should perhaps consider not annoying me" Harley said mimicking his tone.

"You wouldn't!" Sirius dramatically exclaimed.
"Would too"
"Harry, save me from this evil monster of a daughter " Sirius said pulling Harry towards him.
Harry laughed.

"You think this is laughing matter? The only thing preventing this fiend from attacking me is your presence "
"Perhaps you shouldn't have annoyed the fiend in the first place? " Harry asked

"Betrayal! " Sirius gasped "Et tu Harry? I angered the fiend for your sake"
"The fiend can hear you, you know " Harley said quietly.
"And she's coming to your place, where there will be no reason for her to hold herself back " Harry added

They almost reached the main entrance /exist of the Kings cross now, and Harry spotted uncle Vernon, who was checking his watch and tapping his foot impatiently. Behind him, in his shadow stood aunt Petunia, her eyes scanning the crowd.

Harley followed Harry's gaze and spotted them too. She grabbed Sirius's arm to get his attention.
"Sirius, I think there's someone I need to meet. Would you like to join me Mr. Black who may or may not have murdered thirteen ?"

Sirius's face paled at her choice of words. Harley bit her tongue. Oops. She hadn't meant to but she had touched a sore topic.
"I'm sorry, I- "
But Sirius cut her off, rearranging his expression to look care free again.

"Yes, we should meet someone, but you should go first, because she might faint if she saw Mr. Black who may or may not have murdered thirteen" He said.

Harley felt that something was off but she knew that Sirius was making an effort to sweep his feelings under the carpet . Seems that she'll have to do something about this but not now. Not when Harry 'oblivious to everything ' Potter was here.