Oh, a Vernon/Petunia love story, thank you so much! Vernon and Petunia are a good team in canon; we always see them work hand in hand and agree on essentials. I like seeing Vernon through Petunia's eyes - even though Vernon is a reprehensible human being, Petunia always gives the impression that she cares for him, that he is right for her. And you show us why she feels like this: Vernon is her rock, her anchor to the normal, safe life that she craves, because magic does not exist, not for her.
The description of Vernon, in his ironed trousers and his buttoned-up shirt, is spot on. Young Vernon would have been a very proper young man.
And then there's the family background that you give her. It adds layers to Petunia's characterisation, and it makes her isolation and her frustration palpable. She must have felt so abandoned and helpless and marginalised, contrasted with her prettier, sparklier, younger witch of a sister. Their mum would naturally dote on Lily, who's magical and brilliant and brings back home stories and charms, whilst reliable, ordinary Petunia is just there. I also very much like that you have Petunia initialise the sex with Vernon, and that he's a gentleman and excuses himself and goes to the bathroom. That's so sweet.
Oh, and the call to Wildlife Control is a nice touch. Very chilling, and very much IC.