A/N: Prompt from apathyempathy, who provided Samchelpez and the first paragraph. Thanks!
Sam felt guilty the instant his eyes lingered on Santana as she bent down to pick up her fallen textbook. He felt guilty, that is, until he caught Rachel doing the very same thing without the slightest hint of regret. If anything… He studied his girlfriend… She looked a little proud.
So he caught her before she left the choir room. “Hey,” he whispered, brushing his lips along her ear, “There something you want to tell me?”
“Sam…” Rachel smiled, a hand coming up to thread through the hair at his nape, pushing up on her tiptoes to reciprocate the kiss to her ear, “I’ve already told you that I’m planning on clearing my weekend to better spend it with you.” Moving her lips along his jaw, she wrapped her arms around his shoulders when he kissed her hungrily.
“Okay,” Sam nodded, “No, I’m very happy to hear that.” He smiled, hands curling around her hips, “I just… Don’t hate me?”
Her brows furrowing, Rachel nodded. “I…’ll give you the benefit of the doubt?”
Nodding again, Sam walked them backwards, retaking his seat he’d stood up from to stop his girlfriend. Pulling Rachel down onto his lap, he smiled lopsidedly, locking his hands back around her waist. “Rache…”
“You…” Sam sighed. There was no point in trying to be vague. Leaning back against the chair, he tried to put the most neutral expression on his face, “…Look at Santana?”
Rachel’s eyes widened. “I… Don’t know what you’re talking about,” she smiled innocently, bending forward to brush her nose along Sam’s.
“Yes you do.” Raising his eyebrows, Sam frowned slightly at his girlfriend. “I’m not stupid, Rache.”
Rachel’s brow furrowed. “I know that. I never said you were.” Touching Sam’s face, she rubbed her thumb along his cheek. “Sam… What is this about?”
“Santana,” he repeated plainly.
“What about her?”
Sam studied her eyes and face, breathing in slowly, equally as slowly letting it out between his teeth. “Rache…” he sighed, shaking his head slightly and tightening his grip on her waist before smoothing down, along her lower back, “You’re attracted to Santana.”
Rachel’s face went white, then red, her body freezing on Sam’s legs. “What?” she whispered, sitting back to stare at him, already shaking her head, “Sam, I’m not cheating on you.”
“And I never said you were.” Smiling slightly, lopsidedly, Sam settled his arms around her waist. “Rache. I never said you were.”
“Then… Then what?”
Sam sighed, managing to do so without seeming like he was making any concessions. “You’re attracted to her,” he repeated. “Don’t try to deny it,” he continued, smiling consciously, allowing again, “I may be pretty, but I ain’t dumb.”
“I…” Rachel’s words died in her throat, her body tensing even more on Sam’s lap, “I don’t…”
Sam shushed her, pulling her into a slow, firm kiss. “Rachel. Aren’t you curious at all why I’m saying this?”
“Maybe…?” Rachel whispered, shoulders wavering in a small shrug, hands sliding back to curl around his ears, her fingers tangling through his hair, “But I don’t know… I’m not sure…” Her teeth worried her lower lip, forehead pressing into his, “I don’t know if I want to hear this…”
Rachel lowered her eyes, not answering.
Sam studied her. “Rachel…” he lowered his voice, stroking her lower back supportively, “Are you… Wait. Do you…” He shook his head, kissing her again, enfolding her securely in his arms, “Are you afraid I’m going to leave you?
“Or,” he continued before she could say anything, “Are you afraid things can change?”
“…Will change,” Rachel corrected quietly, avoiding his eyes as her arms dropped to rest against his chest. “I just. I love you, Sam. I don’t need anyone else. Do…” Her eyes rose, finally, meeting his again, “Do you?”
Sam kissed her softly, reaffirmingly, his arm sweeping up and down her back. “No, promise. I just.” One corner of his lips quirked up. “It’s obvious you’re attracted to her. And, to be honest, I still am too.”
Though she didn’t look surprised, Rachel let out a deep breath, nodding slowly. Her hands flexed in his hair, spasming before falling to rest on his shoulders, her body lowering to relax into his; her cheek brushed against his neck, and she slipped her arms around his chest, “Sam, I… There’s something I have to tell you.”
The tone of her voice made Sam’s heart trip, a slight frown rising to his lips a second later. He stroked her back, “Yeah?”
“Before… Before I got together with you, I…” Rachel shifted, sighing, fingers coming up to grasp his shirt.
“…Slept with Santana.”