Author's note: I wrote this awhile back and posted it on my AO3 account (GeekofKhaos), but decided to cross-post it here as well. This shit is rated M. Kids, git on outta here.

Surprise

Wendy's stomach hurt. She was a nervous wreck. She was finally going to see her boyfriend in person for the first time—since they'd been dating, at least.

When Dipper Pines had confessed his love for her during his first summer in Gravity Falls, Wendy had been too scared to act on it. The following summer, Dipper had pretty much left it alone. He even began dating Pacifica Northwest, much to Wendy's chagrin. That was short-lived, however. They broke up soon after the Pines twins headed back home to Piedmont for the school year. Wendy tried to console Dipper over the phone and via text, without resorting to bad-mouthing Pacifica too much. It had been difficult.

It was around that time that Dipper confessed, via text, that he still had feelings for Wendy. Scared to miss what might be her last opportunity to be with the boy she loved, Wendy had confessed her feelings as well. The two officially became a couple that winter. Texting, calling, and video-chatting became their lifelines.

It was finally June. Dipper and Mabel were due to arrive back in Gravity Falls today. Wendy would finally be able to embrace Dipper, kiss him, and touch him. Their texts and phone calls had gotten a good deal more frisky in the past couple weeks, and she knew that Dipper was hoping to get physical as soon as possible. After all, he had told her, he'd been waiting for this for three years now.

Wendy longed to feel the touch of Dipper's skin against hers, to feel their warm bodies pressed together, limbs entwined. But she was also terrified. He was her first. And there was something about her that Dipper didn't know. Something that might make him hate her, and want nothing more to do with her.

Wendy bit her lip and paced her bedroom, trying hard to take deep, even breaths. She stared at her phone, willing the text notification to trill. Her dad and brothers were gone for a few days, camping. The plan was that Dipper was going to text her as soon as he and Mabel got to the Mystery Shack, and she would go meet him in the woods between the Corduroy cabin and the shack. Then, they'd head back to Wendy's house and… neither of them had said it explicitly, but they were both thinking it. They were going to fuck.

Wendy's heart nearly beat out of her chest as her text notification finally beeped.

At Mystery Shack. Meet you halfway. Love you.

Wendy took a deep breath, and, fingers shaking, texted back.

Love you too. See you soon.

#

Wendy heard Dipper before she saw him. She was going to have to teach him how to tread lightly in the woods this summer. If, that is, he still wanted anything to do with her after today.

Wendy leaned against a tree, and waited for him to approach. "Hey Pines," she said as soon as she saw him. She meant for it to sound confidently casual, but her voice was shaking.

"Wendy!" breathed Dipper. He made no attempt to sound casual. He ran for his girlfriend, and embraced her, picking her up off her feet, and twirling her around. He'd grown a lot in the last couple years. Gone were the noodle arms and legs, replaced by sturdy muscle. He was as tall as Wendy now, too. He gently placed her back on the ground, and pressed his mouth to hers, softly at first, and then with fervor. It was their first kiss, and it was spectacular.

Wendy hoped that it wouldn't be their last. She pulled away from him, trying to keep him from seeing her tremble. If he noticed, he didn't say anything. He grabbed her hand, and they began walking back toward the Corduroy cabin.

"I missed you," he said softly, squeezing her hand.

Wendy giggled. "You missed me? We've talked multiple times every day since we officially became a couple."

Dipper grinned. "I missed being in close, physical proximity to you, then. Is that better?"

"It'll do," said Wendy with a nod.

They walked in amicable silence for awhile, just happy to be near one another. However, the closer they came to her house, the more Wendy struggled to control her trembling. Dipper noticed.

"What's wrong, Wen?" he asked softly, as they approached the cabin. He stopped and turned to face her.

Wendy's chin quivered. "I'm nervous," she mumbled. It wasn't a lie.

Dipper pulled her close, and kissed the top of her head. "We don't have to do anything you don't want to, you know that, right?"

Wendy laughed wetly. "That's not it. The things I want to do to you..." she stopped talking, and groaned.

Dipper's face flushed, and Wendy looked down to see a noticeable bulge in the front of his jeans. She took a shaky breath, and placed a hand against his face.

"Come inside."

#

She had meant to talk to him before they did anything. She really had. But once they got to her bedroom, all she could think about was the bulge in his pants.

Wendy shut the her bedroom door firmly, and then turned to Dipper, gazing at him seductively from under her eyelashes. She strode up to him, and pushed him back onto her bed, then straddled him.

"I...I thought you were nervous," stammered Dipper. Wendy's answer was to begin unbuttoning his shirt.

He was more muscular than Wendy had realized. She ran her hands over his well defined pecs, and the outline of his abs. Then she bent down, her long red hair cascading over his body, as she began to lick and suck at his nipples.

Dipper panted and groaned loudly. "We-Wendy, what's gotten into you?"

She crawled her way up his chest, to answer him face-to-face. "Hopefully you, soon," she said, her voice husky. She pressed her mouth down on his forcefully, prodding her tongue between his lips, and moaning into him. Dipper clung to her desperately, overwhelmed by the sensation of her body pressing into his. He moved to reach for her pants, but she quickly jerked away.

Wendy pushed herself off of Dipper, and bit her lip. What was she doing?! She had to tell him. If it was a surprise, he'd hate her for sure. She wanted him more than anything, but she knew she had to be honest with him.

"Wendy, what's wrong?" asked Dipper, sitting up, concern etched across his features.

Wendy couldn't meet his eyes. She looked at the floor, and clasped her hands together nervously. "Before we, uh, take things any farther," she said quietly, "I have something to tell you. Something that might change how you feel about me."

Dipper grabbed Wendy's hands, pressing them to his chest. "Am I not your first? I know you said I was, but I don't care if I'm your first or your fiftieth, Wendy. I love you."

Wendy shook her head. "No, it's not that. You really are my first—which is why this is so scary, and I have no idea how to tell you."

Dipper reached forward and crooked a finger under Wendy's chin, tipping her face up so she would look at him. Her eyes were glistening, and her chin was trembling. He'd never seen Wendy this terrified before—not even during Weirdmageddon. He leaned in and gently kissed her forehead.

"I love you, Wendy. No matter what you tell me—I love you."

Wendy nodded, and took a shaky breath. She looked down at her hands again, afraid to see what expression her news would inspire.

"Dipper… I'm trans."

Dipper was quiet for nearly a minute. Wendy's whole body was trembling. She finally had to look at his face. She needed to see if he hated her now.

Dipper's expression was bemused. Wendy had not expected that. "Well?" she asked. If he was going to reject her, she wanted to get it over with.

"You're a trans...girl?" he asked hesitantly.

Wendy nodded. "I was born Wendell Corduroy, but I knew as early as five years old that I was really a girl. Luckily my dad is more understanding than his gruff demeanor would suggest—when I began to go through puberty he got my doctor to prescribe T blockers and estrogen. That means my boobs are real. But," she paused, and swallowed. "I haven't had bottom surgery..."

Dipper's expression didn't change. He still looked bemused. Not angry. Not disgusted. Just thoughtful, and slightly surprised.

"Huh," he said finally.

Wendy was beginning to get frustrated. If he was going to dump her, she wanted him to just do it.

"Huh, what?" she asked, crossing her arms over her chest.

"For a long time I toyed with the idea of telling you this, but since we're in a male/female relationship it didn't seem particularly relevant," said Dipper, a grin slowly spreading across his face. "But it might make you feel better to know that I'm not actually straight at all—I'm pan."

Wendy blinked at Dipper. "Pan?"

"Pansexual," nodded Dipper. "As in, it doesn't matter what you've got going on between your legs. I love you, Wendy. All of you. As you are."

Wendy felt hot tears begin to roll down her cheeks. She hadn't dared hope for such an outcome. Dipper leaned forward and took her into his arms, and kissed her tears away. She nuzzled into him, pressing warm kisses into the pulse point at the base of his neck.

"If-if you're not ready I'll un-understand," stammered Dipper, shuddering. "But if that's the case, maybe you shouldn't… do that."

Wendy's answer was to finish yanking his open shirt off, and push him down onto the bed once more. She straddled him, quickly unbuttoned and tossed aside her favorite flannel shirt, and peeled off her tank top. She didn't have a bra on.

Dipper groaned and reached up, cupping the soft globes of flesh in his hands, worrying her tender pink nipples with the pads of his thumbs.

Wendy moaned, and threw her head back. The bulge in Dipper's pants was hard as steel, and huge now. She rocked her pelvis, grinding against him, eliciting a whimper of pleasure from her boyfriend.

She slid off him, and grabbed the waistband of his pants. He leaned up, resting on his elbows, as he watched Wendy unbutton, and slowly unzip his jeans. His member strained against his boxer briefs. Wendy pulled his pants all the way off, then followed suit with his underwear. Wendy stared at his cock for a moment, surprised at the massive size of him.

"Is-is it okay?" asked Dipper self-consciously. This was his first time, too. Wendy met his eyes and nodded. She licked her lips, and took his cock in her hand. It was hot to the touch. Dipper moaned loudly as she leaned forward, and experimentally swirled her tongue around the tip, and then kissed the small slit, which glistened with pre-cum. Feeling bold, then, she took him into her mouth.

Dipper grunted, his hips bucking instinctively. This caused his cock to slide all the way into Wendy's mouth, touching the back of the surprised girl's throat.

"S-sorry!" he said quickly, but Wendy kept his entire cock stuffed in her mouth, and stared at him with big, wet eyes. She moved on him, sliding her tongue along the sensitive flesh at the tip, moaning against his rock hard cock. She gripped the base of it gently in her fist, and pumped up and down, her hand in time with her mouth.

Dipper groaned, thrusting his hips to meet the movements of Wendy's mouth. His groans turned to whimpers, and he began panting.

"Wen-dy I'm—hnnng-gonna c-cum," he managed to pant out, his voice strained.

Using her free hand, Wendy gently cupped Dipper's balls, and gave them a small squeeze. It sent him over the edge. Dipper cried out, and Wendy felt his cock spasm in her mouth as hot, salty liquid spurted down the back of her throat.

Wendy greedily swallowed Dipper's cum, and waited until his cock stopped spasming before she finally pulled her mouth from him, giving one last kiss to the wet tip. She crawled up beside him, and nuzzled into his side. His chest was heaving as he tried to catch his breath. He turned to face her, his eyes slightly glazed, and smiled.

"You're amazing," he whispered. "I love you so much."

Wendy grinned. "I love you too, dork. Don't pass out on me though—we've only just begun."