Disclaimer: Dreamworks and/or Cressida Cowell own the characters in this, not me.
SPOILERS. Ish. Possibly. If you haven't seen the footage that the President saw, it might be spoilery. If you haven't seen "Gift of the Night Fury," it might be spoilery. But not majorly spoilery, just spoilery of a tiny but wonderful detail.
And with those awe-inspiring words, prepare to be further underwhelmed.
Astrid Hofferson did not blush.
Oh, she flushed red with exertion and anger; when she felt helpless with frustration deep pink would tinge her cheeks (it was a giveaway, and one she had to work on controlling). But she did not blush. Not from shame, not from embarrassment, and definitely not from stupid, giddy, girly pleasure.
So it was a bit of a shock to feel her face warm when he talked to her. (Of course it was him. No one else could treat her the way he did and live to tell the tale; no one else could surprise—no, trick her own body into betraying her this way. It was infuriating. Maybe that was the real source of the red cheeks.) At least it wasn't every time he spoke to her—gods, how embarrassing would that be, to lose control whenever he said her name? Luckily it was only sometimes, and those times were when nobody else was likely to hear.
Her parents weren't big on nicknames—there was no real way to shorten Astrid, at least not to anything she'd stand to be called. Mostly they used her name or "daughter." Pet names were no better; they all sounded to her like things she most definitely was not: sweetheart, honey, darling, babe. She was a warrior, not a baby to be coddled or a weak-willed girl to be flattered and charmed. Snotlout had learned not to try any of them on her, and for a while she'd thought everyone had learned from his painful example.
Except him. Of course.
The first time had been the worst. She had gone to Gobber's shop to get her ax sharpened and found it unusually quiet, even though she'd overheard Tuffnut saying he was working on something there—not that she had been looking for him at all. "Gobber?" she'd called, and then, venturing deeper into the forge, "Hiccup?"
He'd emerged from a nook in the back with a warm smile. "How can I help you, milady?" he'd asked, and she had most definitely not blushed.
She would admit to her eyes widening, though, and her fingers tightening unconsciously on the handle of her ax, a movement that, however small, hadn't escaped his notice. To his credit he hadn't apologized the way he once would have done; his smile had faltered briefly, but he hadn't flinched away from the fist he surely expected. In her shocked state all she'd been able to do was shove her ax at him and mumble something about sharpening, and he'd taken it, smile widening, and moved too close into her personal space to get to the grindstone. Once he'd finished she had rushed away, barely able to mutter her thanks and make it out of the shop without sustaining some serious injury to her suddenly clumsy and traitorous body.
Thinking about it later, when it was easier to ignore the warm fluttering in her belly his words and the tone of his voice had conjured, she knew she shouldn't have been so surprised. He was constantly calling Toothless "buddy" or "bud"; she'd just assumed the endearments were reserved for his best friend. If he called her by one, then it meant that she meant something to him.
And his choice of word—milady! So many things about it should have offended her. She should have protested that she was no lady, and she certainly wasn't his. But instead of anger at his presumption, her response had been a thrill of excitement at the possibilities the word suggested, of power and recognition of her skill, but more of one day being not just any lady, but his.
If she blushed then, it was excusable, since there was no one around to see it.
Over time she got used to him calling her milady, until it no longer caused heat to flood her face to hear him say it. The pleasure it inspired never failed, though; it was a reminder that he knew her better than anyone else, and that he still desired and admired and liked her, enough to risk rejection and bodily harm to confess his feelings in that one word.
So one day when he took her hands and asked her to become his lady in every true and legal and permanent sense, she didn't blush. But she did say yes.