OK, this was a little one-shot that came from a notion about writing a sex scene that wasn't about showing "the best sex ever." I wanted to find a circumstance and write a scene where one partner basically used the other for selfish pleasure - but at the insistence of the "used" party. It was a personal challenge, to come up with plausible circumstances where such could happen without either party seeming like they were exploited or used or just plain selfish.
And Booth's return from prison seemed like the right circumstance. Bones' motivation was to reinforce to Booth that he was home, that he was out of prison, and she was welcoming him back wholeheartedly and without reservation. To her, that meant focusing entirely on getting the deed done as quickly as possible, with zero hesitation whatsoever. If that meant that she didn't enjoy it as much as he did, or it might even be a little uncomfortable, so be it - the whole point of the exercise was to restore their relationship to as close as it had been pre-prison as possible, as quickly as possible. And that would, necessarily, mean that it would also be exceptionally satisfying for both.
Her choice to use the traditional Catholic wedding vows during sex was also deliberate. She knows that Booth holds his Catholic faith very strongly, and that she doesn't. By using the familiar form, and meaning it, she is recognizing the importance of his faith to him and accepting it. She isn't Catholic, or even a believer, but she was saying that she accepted fully the terms of their marriage - and they are his terms.
I'm glad that the reviewers thus far seem to have picked up on my intentions here in this story, and appreciated it.