Watching Billy slip through her window late at night made Sidney nervous and not just because her father was down the hall.

It made her nervous because she wanted to try something with him, something that Tatum had told her about earlier in the night when they'd spoken on the phone.

That something was called thigh riding. According to Tatum, thigh riding was when a girl straddled her boyfriend's thigh and ground her pussy against it, her clit often rubbing against his skin (if they were naked) or his pants (if they were clothed) to the point in which she came. Tatum told her that some girls did it to tease their boyfriends, while others did it to experience sex without penetration.

Sidney wasn't ready yet to give her virginity to Billy, but until she was, she wanted to know what thigh riding felt like. She just hoped that Billy would be receptive to the idea.

'Who are you kidding? Of course he'll be receptive to it; he's a teenage boy.'

Sidney shook her head and stepped closer to where Billy was standing, staring at her pictures and everything else that were hanging on her walls and sitting on her vanity.

"Hey, Billy," she began, watching as he turned to face her, his brows raised in question.

"Yeah?" He asked, staring curiously at her as she bit her lip and hesitated for a moment. "What is it, Sid?"

"I was talking to Tatum today and she told me about something that I was hoping we could try together."

"Oh?"

The soft pink blush that dusted her cheeks only piqued Billy's ever-growing curiosity. "Sid," he began, taking a few steps towards her. "Is something wrong?"

"No, no, nothing's wrong," she reassured him. "It's just…" she played with her hands and blurted it out: "I want to try thigh riding if you're up for it!"

Billy's eyes widened and his mouth dropped open a bit. Of all things he was expecting Sidney to tell him, that definitely wasn't one of them.

For a few minutes he floundered, his tongue temporarily ceasing its function. Then, closing his mouth and clearing his throat, he asked her, "You…you want to try thigh riding with me?"

Sidney nodded, her face now a dark red.

"And that's what you and Tatum talked about today?"

Another nod. A darker blush. Her hands were twisting more frequently now, her fingers repeatedly interlocking.

"What made you decide that you wanted to try thigh riding?" Billy inquired, stepping closer to her and moving so they were sitting beside each other on her bed.

'He's not rejecting the idea and thinking I'm weird. So far, so good,' Sidney thought before answering him aloud, "Tatum was telling me about it today. She says that girls tend to like doing that for their boyfriends because it gives them both some kind of sexual satisfaction without actually having sex, and I know that you want to have sex but I don't yet, so I figured that we could try doing this because she also told me that girls suggest it so they can make their boyfriends happy while also retaining their virginity and—"

She was cut off by a pair of soft but chapped lips connecting with hers. The kiss was slow and gentle, but still held the same passion that the fiery, hungrier kisses they would have when they both wanted something more. Billy's fingers made a small caress to the side of her neck, a moan involuntarily slipping out of her mouth at the touch. Then he was pulling away, a small smile quirking his lips upwards and his warm eyes boring into hers.

"I would love to try thigh riding with you," Billy began, his hand still resting on her neck while the other moved to her side. "But I don't want you to do it because you want to please me. I can do that just fine. I want you to want this because you choose to. I promised you that I would wait until you were ready to do anything sexual and I'm not breaking that promise."

The loving words made Sidney's heart flutter, her body relaxing into his hands. "I want this, Billy," she whispered, turning her cheek slightly so she could drop a kiss to his open palm.

Billy kissed her again and adjusted them so she was in his lap, balanced on his thigh. "Go on, then, baby girl," he murmured, staring up at her with half-lidded eyes. "Ride my thigh."

Sidney blushed, rocking slowly back and forth on top of his thigh. The rough denim of his jeans felt amazing against the thin fabric of her panties, rubbing against her pussy with a wonderful friction. It took her a few minutes to get used to the feeling, but when she did and she established a rhythm, her eyelids slid shut and she tipped her head back, moaning softly at the sensual scratching that his jeans caused against her clit.

"Fuck, that feels so good," she whined, her hands now resting on his chest as she quickened her pace, needing more of him.

"Look how eager you are. You like getting yourself off on my thigh, yeah? Keep going, baby. Take it."

Billy's dark, encouraging purrs made Sidney wetter and ride his thigh harder, pressing down on him with every forward roll of her hips so her pussy and clit got more attention. Whines and whimpers fell from her mouth as she really started to bounce on him, the stimulation so intensely pleasurable she imagined herself actually riding his bare cock and not his clothed thigh.

"Oh God, ohgodohgodohgod, fuck!" Sidney cried, her body heating up, breaths coming out in huffs, her nipples hard through her nightshirt.

Billy was tempted to pinch those stiff peaks, but he refrained from doing so. It was so much more satisfying watching his sweet, innocent, little virgin girlfriend work herself into a frenzy just by touching him.

"You look so beautiful riding my thigh like this, baby. Are you gonna cum?" He asked, not taking his eyes off of her for a single second.

"Yes," Sidney panted, her hips moving faster, desperately wanting to go over the edge.

"Cum for me, baby girl. Cum for Daddy."

Sidney arched her back and let out a cry of ecstasy as she fell over the edge, cumming hard all over his thigh. She could feel her pussy pulsing around nothing, hips stuttering as she continued her movements to prolong her orgasm. Her clit was swollen and her now ruined panties caught on his jeans with every thrust of her hips, intensifying the feeling. Finally, she finished and she slumped down on his chest, her body trembling and breathing harsh.

Billy's fingers slowly stroked up and down her back, nightshirt damp from sweat, trying to coax her through the aftershocks. "You were so good, baby," he praised, kissing her ear.

"What…about…you?" She asked slowly. She knew he was aroused by her actions, but she doubted that he came.

"Don't worry about it," he said. "Trust me, I can take care of myself later and I'll have some amazing images to get off to."

Sidney exhaled a laugh and cuddled into him, once again mentally thanking her best friend for being so much more experienced in sex than she was.