This never happened but it would've been awesome. Excuse my Sachiko fail.
Erza had one leg over Sachiko's window sill when the girl cried out, "Stop!"
Erza halted instinctively and cleared her throat. "I'm already up here now," she explained, a bit of irritation beginning to color her tone. Sachiko was always the most ridiculous at the most inconvenient times.
"I...don't think you should come in." Sachiko's voice shook at the last few words, and Erza ignored her irritation to take the final steps into the room. She nearly stumbled over a chair in the process, and bit down the curse she knew was coming. It was...curiously dark, moreso than usual. Her host was turned away from her, seated in a far-off chair with her shoulders hunched. Erza frowned and mentally went through what could possibly be wrong. With Sachiko, it could be something as minor as a teacup breaking or something as devastating as being attacked by a disgusting brute of a vampire. Who knew?
Erza felt guilty for that cruel thought. She'd been trying to remember that the worlds they came from were very, very different. If Sachiko was upset about something, either minor or major, she had the right to be. And Erza was her friend, so she would have to remember to be supportive and not condescending. "Is there something wrong?" And another, horrifying thought: "Did someone hurt you again?" She hadn't seen Sachiko yesterday...
"No, there's nothing at all." Erza saw Sachiko shift in the chair. "I'm just...I'm not in a state to have guests at the moment."
Instead of saying anything particularly pushy or biting, Erza was silent, and waited. It took a very long time for Sachiko to speak again.
"I...appear to be stuck in a costume and it's created a few...adverse effects."
Ah, was that all? Erza shrugged her shoulders. "The costumes are annoying, but it's hardly anything to be upset about, Sachiko." She kept her voice calm and even, making it clear she wasn't trying to undermine her friend's discomfort. "But if you'd like me to leave, we can talk..." She trailed off as Sachiko turned around. Now that she had a clear look at the outfit, it appeared to be that of a traditional vampire count's, cape and all. Sachiko was very, very pale, so much so that her skin was luminous in the pale light. The unpleasant bite on her neck was gone. Her eyes were fever-bright, and she looked very close to tears.
"See?"
Erza felt the costume was cruelly ironic. "Oh." She coughed. "You have fangs?"
Sachiko grimaced. Erza saw the fangs. "They're difficult to talk around. I keep cutting my tongue. And I'm..."
"Hm?"
She glanced down, and her voice was scarcely a whisper. "Thirsty. I tried water, and tea, but..." Her voice was trembling again, and so Erza reached over to give her hand a brief squeeze. She was as cold as ice.
"I see." Erza blinked, and her eyes widened. "Oh. I see." Ah. This was...ah. She was trying to think of something to say, or do, and Sachiko appeared to be working herself into an anxiety attack.
"It's absolutely dreadful! What am I supposed to do? I can't...I can't hurt someone like that! Not after that man..." Her hands clenched into fists in her lap, and Erza said the only thing she could think of.
"Well...you certainly can't starve to death. If the victim is willing, it won't be too terrible, correct?" Sachiko stared at her in wide-eyed shock. Her eyes, Erza thought for the second time, were very blue, and she wondered why she was thinking about it, or why it mattered at the moment.
"I couldn't!"
"You have to," Erza's voice was firm. "I'm sure you won't kill me, and I've dealt with worse than a bite on the neck." But she did not tug Sachiko over to her, as she would in any other situation. Instead she sat on Sachiko's bed and waited for the other girl to come to her. There was another overlong moment, and finally Sachiko did come to stand over Erza. She looked very upset, and annoyed. Erza didn't mind. It was better than having her go into a panic.
"You are the most ridiculous person in the world."
A long-suffering sigh. "Let's go ahead and get this over with."
Sachiko frowned, hesitated, and said, "Close your eyes."
"Why?"
"I don't know! I'd assumed you didn't want to see your neck being bitten into!"
Erza closed her eyes.
There was nothing at all for a moment, no movement from Sachiko, and Erza herself had fallen very still. Then she felt hands on her shoulders, and breath(it was cold too) ghost across her neck.
Erza wished you could consciously control goosebumps.
"If I hurt you, tell me to stop. I don't care if you think I'm overreacting or not."
"I'll tell you." Why were they both whispering? She heard Sachiko take one deep breath, felt the hands on her shoulders tense, and then she felt the bite. It didn't hurt at first--it was just a bit of pressure, but then Erza jerked reflexively when she felt the fangs break her skin. Sachiko froze, and Erza managed to speak.
"It--it's fine. It just...." Her breath hitched. "It startled me. Go ahead." So, Sachiko went ahead. The pain wasn't too bad, Erza realized when she felt the fangs slip completely into her neck. Barely any pain at all, and it was giving way to a not entirely unpleasant pressure. Luckily, Sachiko didn't seem to be the same breed of vampire as that man had been. She gradually relaxed in the other girl's hold, and in response Sachiko shifted closer. It wasn't bad at all.
When she started to suck at her neck, however, that was an entirely different feeling. It was, Erza thought, not at all unpleasant. In fact, it was very pleasant, and she couldn't quite keep from making a soft noise in the back of her throat. Sachiko didn't hesitate this time, or stop: in fact, the noise seemed to spur her on. She had shifted so close to Erza now that she was practically in her lap, and so Erza felt it wouldn't be too terrible to simply pull her the rest of the way. And that seemed to encourage Sachiko, because she went to tangle her hands in Erza's hair, and the bite deepened, but Erza found that it didn't hurt at all. In fact, it was doing pretty much the exact opposite of hurting.
It was a long time before Sachiko pulled away, and Erza thought(or imagined) she felt the girl briefly lick at the spot she'd bitten. She sighed, and her hands tightened around Sachiko's waist. She very slowly opened her eyes.
Sachiko was flushed. She was breathing rather heavily, and her eyes were very...strange. She had never seen her look like that before. It was...well, a hungry look. Erza felt something very similar to what she'd felt a few moments ago when Sachiko was sucking at her neck, but managed to rein it in. "Sachiko? Are you alright?" Her voice sounded very far away, even to her own ears.
That seemed to snap Sachiko out of her stupor, and she scrambled out of Erza's arms, standing to her full height. Her voice sounded tight and high-pitched. "Um, yes. Yes. I'm fine. I feel much better, thank you."
They stared at one another.
Then Erza stood(very slowly, she felt a bit lightheaded), touched her neck to see if it was still bleeding, and made her way back to the window. "Good. I'm glad I could help."
"Thank you."
"Yes. I..." She glanced over her shoulder at Sachiko, and before she climbed out of the window, she said,
"I'll see you tomorrow."
Sachiko coughed, and her strange eyes glowed a little brighter. "Of course. I'll see you tomorrow."