Sex has as much to do with parenting as a car manufacturer has to do with how the new owners take care of their new car. Most anyone can have sex and create a new life. Unfortunately it has proven time and time again that being able to produce a child is no indicator of how one will care for a child. So I would say, sex and sexuality are not foundational to parenting.   Commitment is something we hope to attain, but few ever do attain true commitment. The only commitment that a child needs is a commitment from an adult that the child will be raised in a loving and secure home. The idea of the nuclear family is a nice thought, but so is winning the lottery   Marriage could be grouped with commitment, but I will address marriage separately. Marriage is not the end all of our existence. Marriage will not define us as people, nor will it define us as parents. There are many marriages where alcoholism and abuse of all natures takes place. The fact that the people are married has absolutely nothing to do with how they will conduct themselves, as people, or as parents. People are people, a marriage certificate will not change them. What will change them is not filed with the records department, instead, it is found within themselves. They need to have a true desire to want to change.   Divorce often effects children more than any adult should allow it to. Parents fight over material things, and mixed in that fight more often than not are the children. Divorce is a battle where adults act out their frustrations, and play petty games, all the while the Lawyers get richer. The true casualties are the children. Children with little, to no life experience in this area. Divorce is not part of parenting. But it can be a test of your ability as a parent.   The foundation of a home is strong. Many times in disasters we see homes destroyed or even taken away by wind or water. The one thing that remains to let us know that there was a home there is the foundation. The things mentioned above are not what I would consider foundational. The strongest foundations are not pieced together, but are one solid structure. My foundation which I choose to build my relationship on with my children is love. No matter how strong the storm, or how high the flood waters when the storm has passed we will still have a solid and stable foundation on which to rebuild.

No I would not agree. Happily sex in the 21st Century is is an experience which can be enjoyed without fear of parenting [unless that is what you want] . Contraception has come a long way.
 I understand that if you have religious convictions, then you may be tied down by what you choose to interpret from the Bible.
I am not advocating sleeping around, but nor am I advocating marriage. I do not run with the celibacy before marriage lobby although I agree with  fidelity in a loving relationship.

How far back down evolutionary history do you want to go? Even in early times, people were having sex with very little successful means of contraception and it was just like playing Russian Roulette for them. The only way for a woman not to get pregnant was to either abstain or let the man take his pleasure in 'other ways'. If you mean did they nominate a partner to be a parent then I guess you must mean in a metaphorical way. I would still say no.

I'll give them a shot, but I prefer to make my own entries short--my own limitation, not meant to be a criticism, sorry if it was taken as such. And perhaps I will spend too much time on things that are "a nice thought." but that is how I think. Would you agree that people who tend to take good care of their cars are also more likely to research the safety, and maintenance and repair history of car manufacturers? I have no basis for this pure speculation. It just seems sensible to me that those characteristics would go hand in hand. I would be willing to forgo the "foundational." I think it is important to parenting in the same way as all teaching. Teaching children a context for sexual behavior is important, just as teaching them hygeine, nutrition, goal setting, and social skills are important. And teaching goes better if example matches precept. thanks for the opportunity to clarify my fuzzy thinking and sloppy self-expression!

Mutual attraction and chemistry, respect for each other, and the knowledge that you are harming nobody else with your sexual activity. I do wonder why you specify someone of the opposite sex though!