Author's note: I am quite a prolific writer around the internet, but this is only my third attempt at internet fiction, and first erotic fan fiction. I have greatly appreciated the follows and especially the reviews, and am committed to finishing this story in relatively short order. In fact, I had the final lines in mind before I started.

And yes, it will be rated most thoroughly "M."

Dr. Temperence Brennan Engages In Sexual Intercourse

Prologue

"So, Seeley, given any more thoughts about your birthday present?"

Five minutes had not passed Seeley Booth's mind since Bones had first made him the offer for his birthday - she would indulge any of his sexual fantasies, within reason. And she had made it quite clear that her definition of "within reason" was extremely broad.

"Um... a little. Still batting around a few notions. It's incredibly generous of you, and I don't want to waste it on something trivial or give it too little thought."

"You better make up your mind soon. It's tomrrow night, after all."

"OK, then. How about this." Seeley paused to screw up his courage. "I want to have sex with Dr. Temperance Brennan."

Bones leaned back, a bit surprised. "I don't understand. We've been lovers for almost three months now. We've had sex sixty-seven different times - sixty-eight if you count that time with the feather..."

He interrupted her. "I thought we agreed we were not going to mention that incident ever again."

"You're right. But that doesn't change my point - we've had sex on many occasions, in many places, in many ways. The idea of indulging your fantasy was to do something different. Are you saying there isn't anything you want to do that we haven't done already?"

"No, let me explain. Yes, we've made love a lot in the last few months, and it's been spectacular. But that's been Seeley and Temperance."

"And what would be different?"

"When you're at work, when you're 'on duty,' you're an almost entirely different person. You're incredibly observant, incredibly analytical, incredibly professional, incredibly focused, incredibly clinical, incredibly formal."

"Thank you. That's what I aim for."

"I just wonder what it would be like if you were to apply that mindset to having sex."

"I'm still not quite certain what you mean."

"I'd love to see Dr. Brennan having sex, and treating sex like the most important procedure or exam she's ever conducted in the lab."