In "Honorable Infidelity", we have the story of one twin who makes a sacrifice for his brother, having sex with his brother's wife even though they can't stand each other.
The sex in this story was an intense battle of wills, with both man and woman trying to prove they can outdo the other for pleasure. It really was powerful. The "rough" code is more a case of the author being careful than actually an indication of rough sex. It was physical sex, but not rough.
The plot itself is pretty good for a short story,
Technically, the story was very well done, but had a minor typo in it, and one medical mistake. A man with a sperm count as low as the married twin could possibly still do In-Vitro Fertilization (IVF), or the famous "test tube" baby. Artificial insemination would be pointless with a sperm count that low, since that involves pushing sperm into the uterus to fertilize an egg or eggs already expected to be there. A low sperm count such as the one twin had would make that impossible. IVF would still be a possibility, though.
I enjoyed the sheer power found in the sex scene. It was sharply erotic and well written. If you enjoy intense and erotic sex, this makes a brilliant stroke piece.