I unfortunately need to state that I do not approve of any of what follows and though I’ve endeavored to write with a neutral tone — it is somewhat (and probably inevitably) acerbic. This is also related to something I previously wrote on marriage and is intended to demonstrate that social morality is now completely incoherent simply by stating plainly how relationships now function.
When you believe you have fallen in love with someone or find them attractive you can feel free to engage in sexual activity with them once you reach the age of consent. If one of both are under the age of consent, it may still be morally permissible depending on the laws where you reside. If this act is between a biological male and female, you should make use of whatever contraceptives are readily available if you want to ensure this activity remains sterile and no life comes from it. In the event that life does find a way, you may choose to make use of abortifacients and failing that, seek surgical intervention to destroy the life within the womb (assuming you have a female reproductive system). You may also want make use of other bodily orifices to reduce the likelihood of conception to zero. The morality of this depends entirely on your consenting to the activity — assuming you have reached the legal age of consent in the nation you reside in. Sexual activity is both a significant expression of affection but also a emotionless and meaningless physical act.
There have been a few recent updates to this however. A woman can remove their consent after the act depending on their feelings later on. There is no known time limit to when they can withdraw their consent. There is now also the question of what defines a man or woman which is no longer dependent on biology as it had been in the past. The morality of the sexual activity is also no longer limited in the number of participants and for a number of years there hasn’t been any restriction between people of the same sex engaging in sexual activity whether in pairs or groups. In recent years, the age for consent is also increasingly under question and further updates may be required in the future.
Once in a sexual relationship with someone, you may choose to define someone as your “partner”. It is not necessary to formalise this through marriage — though many still choose to. Marriage was previously limited to a man and woman but has now been expanded though the number of people who can be married is still generally restricted to two persons for one marriage. It is not known why this is as there are historical precedents for men being married to more than one woman and there have been some calls for legislation to provide for people in other previously unconventional arrangements too.
Marriage historically has had both civil and religious significance and is usually still formally celebrated. This remains so though some people (as in the past), choose to have small or informal ceremonies but these still must be registered with the relevant state authority. When you get married you are choosing to commit to your partner though this isn’t necessarily for life. People often still pledge to be faithful to their partner for life though what was is generally known as “adultery” is not to be considered morally impermissible as in the past. Evidence of adultery may have legal ramifications if one of the married partners chooses to divorce though the person who committed this may still have felt it was right to do so for any number of reasons. Whether someone thinks it is right or wrong, to be unfaithful is really open to question and most people today will be quite accepting of new relationships forming out of what was previously called “adultery”. Indeed, marital relationships can be defined in many different ways including what is known as “open”. This is when both partners agree for one or both of them to engage in sexual activity with other parties whether separately or together. This has no bearing on the legal state of their marriage which is more and more related to financial and living arrangements.
However you define your relationship, you may choose to bring children into your life. A woman or man (with a female reproductive system) who has become pregnant in any situation described above may decide to keep the child to raise. This can be as a single mother, with a partner or partners or in a legally recongised marital arrangement. If you are in a same-sex relationship or you or your partner are unable to conceive, there are still a number of options for acquiring children. These are expensive but depending on where you live, they may be partially or fully funded by the state through tax-revenue. In these cases the child will only be biologically related to one of the partners but it is highly impolite to point this out.
Even when you have brought a child or children into your life, you have no moral obligation to maintain the relationship that the child was born into. As above, you may change or break your relationships as you desire. Your partner or partners may also do the same. If there is a dispute with regard to custody of the child, this will need to be decided by through the state court system where you reside. In general, people still consider the breakdown of relationships to be regrettable if not wrong but there is still nothing morally wrong with ending a relationship for any reason. This said, the biological father will still often be responsible for contributing to the maintenance of the child whether or not they get custody and whether or not they are responsible for ending the relationship.
This is only a brief overview and I may need to update this in the near future as law, terminology and circumstances continue to change frequently. It is quite possible that some of what I have written may already be unintentionally offensive though I have endeavoured to state everything in plain terms.