It was a good thing that Scorpius mentioned Lori, too, drawing the parallel between him and Severus, because up to this moment, Al's mind filed Lorcan Scamander as 'let inside on an as-needed basis' where the rest of Al's immediate family were currently residing.
Perhaps Lorcan did have the need of spending an occasional night here in nearby future, like Severus would. Only Severus was the secret-keeper and didn't need to be let through the Fidelius. "I know," Al confirmed, making a mental note to ask Severus to write down their new address for Lorcan, even though some perfectionist part of him cringed at the thought of additional security holes by way of additional people, people whose minds and actions changed too fluidly and quickly for the security spells to catch up with them. And this is why one Fidelius only is unreliable and is not nearly enough to protect one's house.
At Scorpius' insistence of not accepting help from Jamie, Al sighed, because there was a part of him which craved that crutch of unconditional help offered by his brother as he craved the security blanket of Jamie's cloak, and the quiet stability of Jamie sleeping just on the other side of the wall.
The money was the undeniable proof that Jamie was here, with Al, in Al's life. That he'd be here, no matter what, like he promised he would. "He's my brother and he wouldn't say something like that without a good cause," Al stated, quietly, believing every word of it.