She glomped him good. And then rolled around. It wasn't on hay, at least. But, to be honest, since this probably happens about 11 months after they confessed, like someone else pointed out, I could see maybe some of that action, as much as I'd like to keep this story PG.
I mean, they basically made out at the top of the rooftop stairs at graduation, after all. Started dating proper in November, first proper kiss in late February or early March as part of a combined valentines/white day/entrance exam celebration day, made out at graduation in March... Yeah, felt like they were really starting to accelerate once that first kiss happened. By Halloween, they'd have been in high school for 6-7 months.
I suppose making out might have been the extent of it for that stretch, but I feel like that's wishful thinking. That kiss opened the floodgates, so to speak.