Ah, this is a gloriously beautiful, unexpected story. I'm so happy to believe that this truly happened between these two. Happened to Sirius (the one I, too, write about) who's in love with a werefolf, and twelve years behind in human touch. I love this fic too siriusly and can't quote on the basis of the fun in the typos.

Just to praise the perhaps drunken but very fitting and effective speed of words and action here:

several to choose from in fact, he says, accio sex box, and it’s not a small box is it, helpfully plonking it self donw just beneath Molly ‘s toes on the b ed and thelid flying open and mollys’ eyes go wide like a kid in a candy shop. Exquisite!

And the depth of the significance this interaction acquires and how you word Sirius's awareness of it:
the power of knowing he’s taken her this way, and something new and tender unfolding in his chest, a fondness he never thought he’d feel. He’s been so angry in his life, he’s hated so many people. Now he’s old beyond his yhears and tired and humbled once again by how wrong he’s been about so much.

This could well be my very favourite among the explicit fics I've ever read. (Note to all other excellent writers of porn: I haven't read many.)

It's wonderful how Arthur is not forgotten earlier either, and this

suspended in the stillness as arthur is suspended

as well as the closing is perfectly marvellous!