As always, both parties are over 18.
Neither has a name given, just nicknames for her, terms of endearment.
Unlike some of the other reluctance stories I've read here, Hers stems from her mind not being fully aligned with her body.
Forgive any errors, I've not had this edited.
Based a bit on my own experiences. I hope you like.
*****
The two best friends lay on the bed, listening to the thunderstorm raging outside her hotel room window. He faced her on his side, resting his cheek on his hand, propped up on his elbow. He delighted in the way she shivered as his hand glided over her belly. When his pinky caressed her flesh just above the waistband of her sweatpants, she gasped and captured his hand in both of hers. It looked so massive in her tiny grasp.
"We can't. I'm married."
He moved his hand to cup her cheek. "Do you want me to stop?" She glanced away. "You're in the driver's seat, my love. Just say the word, and I'll stop." When she said nothing, he trailed his index finger down the side of her neck. Her eyes closed.
"Why do you have so much power over me?"
"You allow it," he rasped.
"I shouldn't."
"Of course you should." He traced the tip of his finger around the base of her breast through her shirt and bra.
"This isn't right."
"Does it feel good?"
"That's beside the point."
He gently cupped her breast. "That is the point." A gentle squeeze. "Feeling good. Feeling what you've never experienced before."
"But I have."
His hand stilled. "Oh? When?"
"Two years ago when you last visited."
"Oh. That doesn't count then."
"Why doesn't it?"
He turned her to face him, his touch feather light. "Because we didn't go as far as we both wanted to."
"We went as far as I wanted."
"Did we?"
"Yes."
"Are you certain?"
"I am."
He stroked her erect nipple through the soft cotton of her clothes. "Why don't I believe you?"
"Because it's easier for you to pretend I want you more than I really do?"
His hand trailed down over her belly, and his eyes followed. When he slipped his hand under her shirt, he glanced back to her own. "You don't sound certain of that."
Her back arched as his fingers skimmed over her skin. "I..."
"Yes?"
A gasp was his only response when his hand once more closed over her breast, this time with only her bra to protect her from his hot touch.
"Baby Girl?" She moaned as his fingertips grazed the top of her left breast. A light scrape of his nail over her sensitive flesh elicited another gasp. "You were about to say something, I think." His voice was amused.
"This isn't fair." Her voice was a whisper, her breathing ragged.
"Oh, this is perfectly fair." She shook her head. "How about if I show you what unfair is?"
"Uh-uh."
"What was that?" He shifted so he was above her, gazing down into her face. Her eyes were closed as she reveled in the sensations he was causing. He rested between her legs, noting how her right heel kept sliding up and down his calf. "Did you say 'Please do'?" She again shook her head. "As you wish, my love."
He slid down her body and pushed up her shirt. His lips touched down, very gentle, on her bare belly. Her back arched. "Please."
"Please what, Baby Girl?" He licked her abdomen. "This?" A moan answered him. "Or this?" His teeth scraped at her tender skin. Her hands came down and she twined her fingers in his hair.
Her shirt slid over her torso, moving just ahead of his magical mouth. The air hit her exposed breasts. Her eyes flew open and she pushed his head back a little. "You can't."
"I bet I can." To prove his point, his tongue flicked against the underside of her left breast. She gasped louder.
"Please stop. I don't want this."
He raised his head and gazed into her darkened eyes. "Liar."
"No. Not while I'm married."
"You realize I can smell your arousal, don't you?"
"I'm not saying I'm not turned on."
"What are you saying then?"
"Just not right now. Please?"
"Would you say why?" She opened her mouth. "Without repeating that you're married."
She sighed and made no move to cover herself. "I don't want to be a whore."
"I wasn't planning on giving you any money for the pleasure I give you." He kissed the tip of her nose. "So, that rules out prostitution."
She narrowed her eyes at him. "Fine. I don't want to be a slut."
"The word slut was coined to attempt to shame women for the number of partners they had, and, in particular, to attempt to control the pleasure they got from sex." He tweaked her stiff nipple between his thumb and index finger.
"Mmm." She opened her eyes again. "If I give in, I'll be a cheater."
"Impossible."
"How so?"
He rolled her nipple. Her back arched again. Her hips matched the movement. "Cheaters never win, remember?" His voice was thick.
Her eyes drifted shut as she succumbed to his touch. They flew open once more when his mouth engulfed her left nipple. "Oh, Jesus!"
Lightning ripped through her body, centered on her tit where his mouth worked at the nipple. Her legs went around his hips and squeezed as the pleasure shot through her. Warmth suffused her body as all the tension left her. "Holy shit," she gasped. "How did you do that?" The words were panted out.
"Cause an orgasm from sucking your breast?"
"Yes!"
"It comes from your level of excitement." He smiled at her.
"That's never happened before." She shook her head. "I didn't know it was possible."
"I know."
"How?"
"You told me two years ago that you almost had an orgasm just from me caressing your breasts." He kissed his way back down her body and untied her pants, pushing them down as he went.
She tried to sit up. "No."
He looked up at her. "I want to taste you."
She moaned at the idea. Once more, he moved further down her body. "NO."
He sat up. "Why not?"