A/N: I finally did this prompt, 3 months later, but I did it. There's not enough Romione in the world and sadly this is a short one but I tried :) I got inspiration from a conversation about unconventional parenthood so...
"It's just that Harry has never been one to take care of himself," Hermione huffs as she brushes the floo powder from her cloak, Ron following behind her.
"But he's an adult now, and he's not our child," Ron answers with a laugh, palm finding the small of her back as they make their way further into Harry's empty flat.
After flicking her wand toward a few lamps, Hermione removes her cloak and gestures for Ron to do the same, tossing them toward the cozy armchair Harry likes to snuggle up with Ginny in on cozy nights in. "First, becoming a legal adult doesn't a responsible adult make, and second since when is Harry not our child?"
Ron stumbles over one of Harry's too old trainers and his face heats. "Unless I missed something –"
Rolling her eyes, Hermione tugs him into the kitchen, clucking her tongue at the cupboard, bare aside from a few packets of crisps and a tin of baking powder. "I mean at school, our little chats, the fireside confrontations, you know. Unless you're thicker than we thought."
With an indignant 'Oi!' Ron pinches Hermione's bum, earning himself a slap, before sticking his head in the cupboard next to hers. "Hermione our son's a disgrace."
The laughter hasn't finished bubbling out of her throat when Ron's broad freckled hand closes over her mouth. Hermione's brow furrows angrily but Ron's already pushing her into the luckily empty cabinet.
The dusty wood shelves dig into her back unpleasantly as Ron leans forward, breath warm against her ear. "I think Harry's home."
Sadly for Hermione, Ron is too perceptive to miss the shiver that runs up her spine, and a chuckle rumbles through him. "Is this a thing for you, then?"
She snorts, shoving at his shoulders. "It was a natural bodily reaction."
Suddenly Ron's mouth is a breath away, his eyes shining playfully in the dim light. "We can talk about 'natural bodily reactions,' but you need to be quieter."
He swallows indignant 'Ron!' and she's pressed more firmly against the shelves, but she can't seem to care when he's nibbling there, and she's nearly forgotten why they're shoved in the closet until Harry's voice rolls through the flat.
Ron pulls away, laughter in his eyes. "I'm not as insecure as young Ron, but shouting Harry's name while I'm –"
She lands a blip to his nose. "Don't be obtuse Ronald. He's talking to someone," she pauses, "he's not alone – it's a woman."
They're practically holding their breaths as they wait for more clues when Ron whispers bitingly, "I knew they were lying about when Ginny got home from away games – bloody hell I'll – "
"Now, you need to be quieter. Honestly, they're engaged and you should be the first to admit your family is a bit – intense," Hermione answers reasonably as she pats his cheek.
Silence falls within the cupboard once again and Ginny's voice drifts through the flat and her tone can't be described as anything but a moan of Harry's name. Hermione clears her throat uncomfortably as a combination of anger and embarrassment brings a flush to his cheeks. "Hermione if you think I'm going to listen to my best mate and my sister –"
"I'm not the one who acted like a common criminal when Harry gave us his floo password," Hermione answers with a smirk.
"No, but you're the one who had to mollycoddle our fake son – "
Now it's Harry's low growl that rumbles through the air and Ron's bursting from the closet, already halfway to the living room before Hermione has a chance to catch up, "Get your bloody buggering hands off my –"
Hermione stumbles around the corner to find a slack jawed Ron facing down a smirking Harry and a vindicated Ginny enthroned on the worn couch, a fair bit of space between them and no sign of adult activities in sight.
"How did you?" Ron splutters.
Harry's bright green eyes dart over to the cloaks draped across the cozy armchair. "I didn't think I had to make a 'no erotic trysts in the cupboard rule' – haven't I dealt with enough traumatizing cupboards and closets for one life time?"
Color rushes to Hermione's cheeks and Ron grunts uncomfortably, knowing exactly what they would've gotten up to if he hadn't –
Then Ginny stands and ushers them toward the floo, tossing their cloaks over their shoulders. "Now if you'll excuse us, my fiancé owes me a proper welcome home."