With regard to leeway, I think we should be mindful of the old saying:
“unity in necessary things; liberty in doubtful things; charity in all things”
Which is to say, where the Church has no clear teaching/doctrine on the matter, individual Catholics enjoy a good degree of liberty in their moral choices. As long as the key principles of sex being unitive and procreative are respected, the Church does not seem to introde further into maried couples sex lives.
