The twins had stuck by Harry through everything simce that first day when they'd helped him load his trunk onto the train.
Even when Harry suspected they didn't believe him, first year they helped him fit in with all the much older Quidditch team.
Second year they'd stood by him as everyone called him the heir of Slytherin. (Which he later learned was actually true, but he wasn't the one petrifying the students.)
Third year they'd given him the map, to escape into Hogsmead and to protect himself.
And this year, with the Triwizard Tournament hanging over his head, Ron had turned his back on him until after the first task and Hermione 2as trying not to take sides, it had been twins sitting in the library until curfew helping him study, ruthlessly pranking anyone who dared come after Harry, helping him practice spells day and night (when he couldn't sleep and they found him in the common room.)
So after Harry had won the tournament, after the resurrection and the Diggory Heirs death had sunk in, Harry had already been halfway through working a contract with his account managers, already did the inherentence and medical tests he needed to prove he was magically recognized as an adult and could organize his own contracts.
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Arthur Weasley hadn't been sure what to think when Harry Potter had approached him after the Triwizard Tournament and gave him a betrothal contract to read over. At the time he'd been amused, but after reading it he called for a meeting with his heir and the Weasley account manager, Slipknot, at Gringotts to authenticate the contract.
Bill had been confused when his father called him to read a betrothal contract, knowing his father never bought into such things, he had been shocked as he read the terms the Potter heir proposed.
A one-sided fidelity oath, Harry Potter would uphold fidelity to his betrothed but did not hold them to that same standard.
A promise to house and support them in any and all decisions, with a frankly massive allowance added to a personal bank account he couldn't take from. They could support themselves off that alone, and that was just pocket money, living expenses and large purchases would be paid for by Harry Potter.
Any businesss, investments, or patents they collected using personal or impersonal funds would be owned purely by them and whoever they choose to share them with.
A minimum of two heirs at least one male to be provided from the union, through any means, in order to have an Heir for both lines on Harry's side.
A single bride's fee paid to the Weasley Patriarch of five-thousand galleons.
The whole contract refered to the twins as one person, but was clearly implying he was asking for both of their hands in marriage.
Bill rubbed his face and called for the relevant account managers to rewrite the contract. Arthur cocked an eyebrow at his Heir.
"The twins will love this, but it's wildly weighed in our favor. Harry apparently doesn't think you'd approve of him." Bill explains, accepting the relevant papers from the two Goblins who show up.
He doesn't recognize either of them but they seem to recognize him. "Master Curse Breaker and Heir Weasley, Lord Weasley, I introduce the Black Account Manager Tornhook, and the Potter now Peverall Account Manager Griphook." Slipknot introduces.
"Well met." Bill nods, looking back down at the provided papers, nearly dropping them as he reads the details.
Both Hook family Goblins grin at him when he looks back up at them. "Yes. The great Heir Peverall-Black has decided to conjoin his lines into the oldest namesakes."
Arthur gives a cursory glance at the page and chokes on his tongue for a second seeing the six ancient and noble lordships.
In the end they sit down with the twins a month later with the three Goblins and the two confused twins with a completely reworked contract.
"Why do we need to look at a contract?" One of them asks, the other continues with "You've never had any of us look at contract but Bill" "and he hasn't signed any."
Bill snickered as he slid the parchment over to them. "Bill thought you'd want to see this one. It was given to me after the tournament, but we've been reworking it over the alst month. I have the original here you can read but I've voided it."
In the end the contract was mostly the same, but most one-sided things were changed to be all-inclusive. There was an option for a closed fidelity oath at the twins discretion, no more open-ended oath, all or none.
A minimum of an heir and a spare for both lines, so four children with atleast two males.
Lord Peverall-Black can hold investments in anything the twins do in or out of the courtship, but cannot own more then a third share or sell to unapproved holders.
Any of the listed on the contract can back out of the betrothal no consequences until the day before the scheduled marriage.
They'd lowered the bride price to two-thousand-five-hundred as that's the most house Weasley had ever charged.
Each twin would accept to take one of the consort titles.
They had sent the contract with Harry's account managers with a note they would show it to the twins pending his approval of changes. He'd sent it back the next day with only the bride price changed back and signed with Hadrian James Peverall-Black.
One twin read the contract while the other read the medical history report that'd come with it. Both took a few minutes, then stopped and seemed to communicate through a staring contest before looking back up at their Lord and Heir, father and older brother.
"This is from Harry?" "Harry Potter?" They asked, looking back at each other after receiving the nods of confirmation.
"How do we sign?" The first twin asked, the second accepting the two blood quills from the goblins.