Note: Before this happens Santana has been flirting with Rachel for months, and they've, let's say, 'experimented' (which might be seen in some flashbacks later on, I'm not sure yet). This starts in the middle of Mash Off, and I'm going to try to keep it canon with other events in the episodes. Enjoy!
"Let's get it going!" Mr Schue yelled eagerly.
"Let's do this," Finn muttered under his breath as...
"ONE, TWO, THREE!" All members of both glee clubs said; if there was one thing that brought them together more than anything, it was their longing to win- even a simple game of Rock Paper Scissors brought out the competition between them. Everyone craned their neck to see the result.
"Ok, paper covers rock," Mr Schue announced.
"YES!" A screech of celebration escaped Rachel's mouth. She and Finn had discussed tactics earlier that day and she had told him to go for paper. He's a good boyfriend, she thought to herself. Cute and submissive- a perfect combination."A kiss for the winner!" Rachel squealed, expecting Finn to walk to her with a smile. But instead it was Santana who waltzed over with a smug little smirk on her perfectly made-up face that could only say that she had won instead.
"That kiss still on, Berry?" Santana raised an eyebrow that slowly crept towards Rachel, who was so shocked by Santana's outright flirting that she couldn't react before their lips were touching and suddenly everything was on fire. The auditorium disappeared, the two teachers present disappeared, the shocked glee clubbers disappeared, even Rachel's seemingly certain sexuality disappeared as the world burnt and smouldered around her and Santana. Rachel couldn't help but wrap her arms around the skinny girl. She felt Santana's fingers grasp her hair and their bodies somehow got even closer. Rachel gasped and Santana took her open mouth as an opportunity and slid her tongue beyond Rachel's lips. Suddenly, Rachel realised just what it was she was doing; she stiffened in Santana's arms and recoiled away from the kiss; just as suddenly as it had started flaming just seconds before, Ohio was now back to normal. Santana's eyes widened with the terrible, lonely feeling of rejection that was settling into her stomach. Rachel grabbed Santana's arm and led her offstage, into the wing and down the stairs to the dressing room.
"What the hell was that about?" Santana was back to her bitchy self, the hurt look gone from her eyes. "Into it one minute, not the next- make up your mind, and quickly, I have to be home by 11 tonight." Rachel glanced at the clock in the corner of her vision and saw that it was only 5 o'clock. She rolled her eyes.
"We can't do this. This cannot happen! I have a boyfriend," Rachel protested.
Santana just smiled her cheeky (and suddenly adorable, Rachel noted) smile and replied, "I don't mind if you don't." Rachel sighed in frustration. She heard footsteps coming down and, realising it must be the Troubletones about to get changed for their performance, she pulled Santana into the neighbouring boys' dressing room as she proclaimed, "I'm straight, for God's sake!"
"Didn't you just hear me? I don't mind if you don't," Santana shot back. "You seemed pretty bi-curious just now, and on Friday night too." She winked, but Rachel's face grew angry.
"You said... You said! You promised you wouldn't tell anyone about that!" Tears threatened to fall so Santana said quickly, "I didn't tell anyone, jeez, calm down!" Santana didn't mention that she had written it in her diary, which Finn, AKA the Blabber Made of Blubber, now had... Rachel turned away but Santana caught her arm and span her back around, taking both her hands and stroking the backs soothingly. "Look, it's alright." The hurt was back in her eyes, and this time Rachel could see it. She wanted to interrupt, say anything to make it better but: "No, no, I'm fine." Santana seemed to sense that Rachel was uncomfortable and dropped her hands, looking at her own white sneakers instead of Rachel's smooth skin. "Just go back up there, apologise to your whale of a man and Mr & Mrs Sequin and you'll be off the hook. I'll tell them it was my fault." Rachel chose to ignore the crude nicknames.
"But... Won't you get in trouble? You'll be accused of minor harassment- that's a week's after-school detention. Not to mention you majorly disturbed the lesson..." She trailed off as Santana raised her eyebrows again.
"Go, alright? I'll be ok. I'm used to it." She winked and Rachel produced a small, grateful smile before she turned and walked back through the girls' dressing room and up the stairs to the stage. Santana heard the girl's muffled voice from above her as she slumped into a chair and sighed heavily. This is going to be a long week, she thought miserably before she got up again and walked through to get changed herself.