Hmmm. Good question. 

I imagine that it took Ron a while to come to the decision to propose. I think it was several years into their relationship. 

Hermione gets in from a long day at work; exhausted from working a difficult case in the Wizengamot. Ron had cooked up her favourite home-cooked lasagne, and had given her a shoulder rub after she finished eating. He then suggested that he give a foot rub. Hermione agrees. 

Ron climbs down, but he doesn’t start rubbing his feet. Puzzled, Hermione looks down and her heart flies into her mouth. 

Ron is on one knee, and is holding out a simple yet beautiful ring. 

Hermione covers her mouth with her hands, her eyes beginning to water with happy tears. 

‘Hermione,’ Ron whispers. ‘I’ve loved you since the age of twelve. You’re my best friend, and my whole world. I can’t imagine ever spending my life with anyone else. You’re wonderful, kind, intelligent, and beautiful in every way. I know I can be a pr*t at times, but what else is new? What I’m saying is… Hermione Granger, will you marry me?’ 

There is a stunned silence. 

‘….’Mione?’ Ron breaths, his old self-doubts resurfacing for a brief second. Before-

‘YES! YES; MERLIN, YES!’ Hermione squeals, throwing her arms around Ron’s neck and kissing him full on the mouth. ‘A THOUSAND TIMES, YES!’

 They stay like that for a while, in each-other’s arms. Eventually, they pull apart, and Ron (grinning wider than he ever has in his life) slips the ring onto Hermione’s trembling finger. 

‘So…’ Ron says, smiling at his now-fiancee. ‘Do you want to keep your own name? Or I can be Mr Granger, if you want-’

‘Ron,’ Hermione grins, pressing her ring finger to his lips. ‘You really do know me too well, don’t you?’ 

‘Well, I try…’ Ron says, happily. ‘Hmmm. How about I become “Weasley-Granger” and you become “Granger-Weasley”?’ 

Hermione tucks a strand of her bushy hair behind her ear, smiling broadly at the man she had loved since the age of twelve. 

‘I like that.’ 

Thanks for the message, @austenpoppy! I hope you liked that! And thank you so much; I’m glad you like my content! (So sorry it took me so long to reply)

Thank you! 

I must admit, I got an virtually request the other week, so you’ll have to forgive me for using the same headcanons. Hope you like these nonetheless. 🙂 

During the lead-up to
the third year exams, Ron noticed that Hermione wasn’t eating at diner. They
started bickering about it, ending up with Ron holding a spoon-full of rice
pudding up to Hermione’s mouth. The rest of the Gryffindor table burst into
laughter, and Hermione sunk low into her seat, blushing like a tomato.

At the start of fourth
year, Hermione was trying to tame her bushy hair, and a curly strand happened
to fall down her face. Without thinking, Ron curled the strand behind her ear.
Noticing her confused expression, Ron felt his ears go red, and he hastily
dropped his hand.

When Viktor Krum kissed
her (a small peck on the lips), Hermione had a mental image of red hair and
freckles. She became so flustered that she hurriedly pulled away from Krum,
mumbled ‘good night’, and hurried off back to the Gryffindor common-room. The
next time she saw Ron, she dropped several books that she was holding, and
couldn’t look him in the eye.

In the second half of
fourth year, Ron developed a tendency to stare at Hermione when she was
reading. He didn’t realise he was doing it until she noticed and blushed
scarlet. Ron hurriedly left the room, his heart hammering against his chest.

In fifth year, Hermione
had a habit of tripping over her own feet and falling into Ron. Harry kept
giggling as he watched his two friends blush furiously.

Hermione once walked in
on Ron having a bath in the prefect’s bathroom. Since his hair was over his
eyes at the time, he never realised. But Hermione spent the next week unable to
look him the eye, without remembering the way her heart had jumped into her
mouth as she watched him bathe.

After McGonagall came
across the two bickering during a prefect patrol, she insisted that they ‘avoid
flirting during prefect duties’. Ron and Hermione both turned red, and avoided
each other’s eyes for the next week. Harry didn’t mention it because it wasn’t
relevant to his journey.

Ron almost murmured
Hermione’s name when Lavender was kissing him for the first time. His ears went
red, and he pulled away from Lavender. Thankfully, Lavender thought he was just
being shy.

After their first kiss,
Ron and Hermione kept accidentally bumping hands as they picked up the basilisk
fangs. As their hands met, their eyes did too; resulting in both of them
grinning giddily, their faces red.

On their first date
(which was to Hogsmeade), they ended up having a ten-minute conversation on
repairing vacuum cleaners because both of them were incredibly nervous.
Eventually, they burst out laughing, Ron put his arm round Hermione’s shoulders
and Hermione kissed him on the cheek.

Thanks again for the request, anon, and I’m really happy you like my content! 

If I remember correctly, Ginny told Ron that in HBP, not DH. Although I find the idea that they kissed before DH quite interesting (I believe Ann Margaret’s ‘Hermione Granger’ trilogy used the same idea, although it was canon-divergent). It’s an interesting theory. 🙂 

As to when it would have been, I think it could have happened after Ron broke up with Lavender, and sometime before the start of DH. At Dumbledore’s funeral, Ron was comforting Hermione in a way he never really had before (holding her close, etc.), and Hermione was much more physically close with him than before. I imagine that, with Lavender out of the picture, it’s entirely possible that they kissed before the end of sixth year. 

How/why did it happen? Maybe one night in the common-room when Harry was busy doing other things, or possibly on a prefect patrol one evening. Ron and Hermione start awkwardly talking about Lavender, romance and stuff, and before they know it, their faces are very close….

Who kissed who? I kind-of like to think that Ron did. I know fanfic authors tend to have Hermione initiate it, but (by that point in the series) Ron was much more confident, and realised that he was actually very attractive. 

Thank you very much for the message, anon; I’m so sorry it took so long to reply (and thank you again; I’m so happy you like my content!).