Prompt: What went through Delphine's mind when she found out Cosima knew she was lying all along?

Betrayal is a Dish Served Lukewarm with Truffles

Delphine set the bag of truffles on the counter, the taste of Cosima's lips still dancing over her own. She grinned. She loved that taste.

She shrugged her coat off and tossed it over the back of a chair as she turned to face the girl she'd fallen so hard for. It was almost scary, how quickly she'd come to want Cosima as more than a friend. Hell, it was strange that she saw her as more than a subject, a thing to study, given that that was the reason she'd gotten to know her in the first place.

And yet, despite the fact that she'd entered into the relationship with a purely scientific perspective, Cosima had easily become someone around whom her actions were dictated more by her heart than her head.

The smile slipped from her face as soon as she saw the expression that Cosima wore. Still slightly breathless from jogging up the stairs in her hurry to meet her girlfriend, Delphine husked out, "Are you okay?"

Cosima, face stony, replied simply, "Are you?"

The corners of Delphine's mouth, previously turned up so giddily, dropped as her forehead crinkled in a questioning frown. "Well, I was, but..." She took a few steps toward Cosima, sat behind her big, solid desk. Her pulse picked up just slightly.

What was wrong?

It couldn't be... No, she couldn't possibly...

Cosima spun her laptop to face Delphine, and the blonde's heart froze in her chest. She was faced with her own picture. Her own face, smiling politely for the camera, plainly aligned with Dr. Leekie and his research team.

Cosima's voice strained as she continued to speak. "Delphine Cormier, not Beraud. You've already got your doctorate in immunology, don't you?" Her face remained impassive as Delphine knelt before her desk.

This was it - the moment she'd anticipated, hoped so desperately to avoid. She was found out. She could feel the whole charade crumbling around her. But there, in her voice - the defeat, the self-disappointment - Cosima had known. Cosima knew the whole time. She'd seen past Delphine's admittedly poor acting and identified her for what she was. Of course a mind like Cosima's would blow right past this weak subterfuge. But she'd gone along with it anyway.

Delphine's heart burned with guilt. A fist grabbed hold of her heart and constricted. At that moment, she would have given anything in the world to have taken a different path.

Her eyes grew even wider than usual as she opened her mouth to apologize, clinging to a wisp of hope that she might convince Cosima to forgive her mistakes. "I... am so sorry."

Cosima brought her hand up to point at her own head. The slightest hint of tears had begun to form in her eyes, and her voice dropped to little more than a whisper. "I am so, stupid."

Delphine's jaw fell just a bit as she reached ineffectively for Cosima across the desk. "No, no. No you're not." She wasn't. Cosima had to be the most intelligent, logical person Delphine had ever met. "You knew this all along."

Cosima nodded, almost imperceptibly, to herself. "Yeah, the transcript you left behind, your fake boyfriend in Paris, pretending you didn't know who Doctor Leekie was; I knew it was bullshit, but I still thought you were on my side." Cosima's voice began to lose its strength. The fist that clenched Delphine's heart tightened its grip. She felt herself physically shrink. She hid her face behind her arms folded over the edge of the desk. Cosima, just out of her reach, looked at her with pain-filled eyes. "I wanted to trust you."

Delphine lifted her head and straightened her back. "You can trust me." You can. Things are different now. Don't you know how I feel for you? I would do anything...

Cosima's voice faltered, but she powered on. "You told Leekie I know these girls!"

Delphine stood and rounded the desk, a primal urge to show her, convince her that she wasn't just using her. She rushed to Cosima and knelt before her knees before she could stand and flee. She had to make her understand. Cosima turned her head away, blinking rapidly. Delphine grabbed at her arms. "I... had to! Look at me." Please. Look at me. "He says you're in danger!"

Cosima finally met her eyes, anger and betrayal and ache evident in her voice as she all but shouted in Delphine's face. "Of what?" She felt Cosima search her face. "D'you - you don't know, do you?"

Delphine bit her lip and shook her head in disbelief at herself. Her vocal chords disintegrated with the realization of her own foolishness. "No," she breathed. Her eyes dropped to the floor.

"Then you're the real danger, Delphine."

Delphine stood in the archway between Cosima's bedroom and living room. She watched helplessly as Cosima threw items of clothing haphazardly into a suitcase open on her mattress.

Her nose ran, and she knew that the rims of her eyes were red and wet. "Please, Cosima." Sniff. "Where are you going?" Don't go. Don't leave me.

Without looking up, Cosima said, in the beaten, broken voice she'd adopted, "Why, so you can tell Leekie?" Another shirt landed in the suitcase. Delphine brought a hand to her head. With her eyes screwed shut, Cosima threw another article of clothing into the bag with great force. She berated herself viciously, "I'm such an idiot."

Delphine cast her eyes away. No you're not. You are wise and beautiful, and I've gone and broken everything.

"What else did you tell him?"

"Nothing!" Nothing. "Just the seven names." She paused. "Nothing about... Kira." She watched Cosima intently to gauge her reaction.

She finally stopped packing her clothes.

Cosima turned to face Delphine with wide, serious eyes. Delphine continued. "She's an anomaly, you know that?"

Cosima's voice grew low. "Delphine, you can use me," I didn't mean to, "that's fine," no it's not, "but don't go near that little girl."

"I didn't and I won't!" I wouldn't. I wouldn't.

Cosima exploded. "Get out!" She pointed wildly in the direction of the door.

Delphine scrambled forward, reaching again for the girl who was so suddenly very beyond her reach. "Please listen to me." Please. Listen to me. "Just let me... tell you this one thing." She sat on the bed. Cosima was trapped between her and the window. "Just listen to me." Delphine looked at her earnestly, poured her heart into her words. "I didn't want to fall for you." It just happened. "I wasn't supposed to." I didn't mean to. "But I have." Her face split into a smile. The truth set it free.

"How can I possibly believe that, Delphine?"

"Because you feel it!" I know you do. "This is not - it's not a lie. It's not possible!" She bit down on her bottom lip. You can't fake this. I can't fake this. It's in my bones. You are in my bones. "You know I've never been with a woman before."

Cosima closed herself. She forced the angry frown on her face to remain as she spat, "Yeah, it showed."

And the fist around Delphine's heart gave a final squeeze - just enough to make it burst.