Prim and proper
Our story starts many many years ago before Vernon and Petunia were married, before they even met in fact. That's where our story starts, when they first met at a dull work gathering Vernon was attending.
Vernon grumbled, "What sort of a party is this? There's no food."
A clear female voice said, "I believe that it's just a gathering, they don't necessarily have food."
Vernon turned towards the sound of the voice and located its owner, a tall slim woman with short blonde hair and dark eyes wearing a neat skirt and a tidy blouse.
Vernon asked gruffly, "Who are you?"
The woman held her hand out and replied, "Petunia Evans."
Vernon briskly shook it and stated, "Vernon Dursley."
Petunia guessed, "You work for Grunnings?"
Vernon nodded and answered, "Of course, why else would I be here? The real question is, why are you here?"
Petunia vaguely told him, "I'm here with a friend."
Vernon inquired, "One of my work colleague's wives?"
Petunia smiled. "Sharp as a knife you are, how did you guess?"
Vernon explained, "It was fairly simple really. Only those who work at Grunnings or those who are related to those who work there come to these drab gatherings."
Petunia giggled. "I only came for my friend's sake."
Vernon leaned closer to her and whispered, "Shall we get out of here and go get something to eat?"
Petunia frowned. "How awfully scandalous, we have hardly met."
Vernon gruffly sighed. "I suppose you're right, what was I thinking?" Before Petunia could reply, he added, "A prim and proper lady like you would never sneak away with someone she just met to get some lunch."
Petunia stuttered, "N-No, that's not it. I just don't want to leave my darling friend alone at this dull affair."
Vernon smirked. "Okay, Miss Prim and proper Evans. Let's see how long we can stay at this gathering without falling asleep. It will be a little challenge for us."
Petunia grinned. "How very scandulous."
She added under her breath, "Let's do it."