Originally posted by FMF
I think that the only criminalized sexual acts should be those that use coercion and/or happen without informed consent. Adultery in many cases may be immoral ~ and may well have serious consequences ~ but I don't think it should ever be an "offense" in legal terms: that would be an intolerable intrusion by the state into the private lives of citizens.
In many countries (the U.S. for example) adultery is
legally regarded as an offense in the sense that it is legitimate grounds for divorce... but you can only get a divorce on those grounds if you are already married.
In an
intimate boyfriend girlfriend relationship one cannot technically commit adultery (one against the other) because an adulterous relationship already exists between them. There is no real (binding) commitment between the two, so "cheating" has actually been on the table from the start of their relationship as a possibility for either one of them.
A commitment may be implied because they presently live together as a couple. But this kind of arrangement is a bit hazy, as it may not mean the same thing to both parties. There is no real agreement here, other than what may or may not be thought of (as an agreement) in the minds of the people concerned. The problem with relationships like this is that one of them may
feel they are soul mates for life, but the other may not feel they are bound by that same level of (undefined, or ill defined) commitment. Some people are okay with this kind of arrangement because of how easy it is to extricate themselves... and then go on to perhaps form other new (non-contractual) arrangements with other new
love interests.
But marriage doesn't exist to only discourage indiscriminate bed hopping, it exists to provide a stable environment for children. Children are extremely dependent emotionally (as well as physically) on their parents, and one of the scariest things any child might have to deal with would be parents who are themselves (emotionally) children.