It's your body, you have every right to decide who you do and don't have sex with(assuming of course the other party is consenting) so why should a spouse or partner feel betrayed if you have sex with another person? And what gives your spouse or partner the right to demand that you have sex only with them and no one else? After all, it's your body.
what gives a partner the right to either request or demand such an agreement to begin with as a condition of the partnership.
A marriage is a legal contract (and is viewed as such in any court of law). A less formal partnership is still an informal contract.
There are entire law libraries which discuss contract law, but I'll explain the basics ... because these relate to everything that you're asking here.
You can't force someone to enter into a contract against their will. If you coerce someone into entering into a contract against their will, it is considered null and void in a court of law.
If someone enters into a contract solely because they were deceived by the other party, and they would not have entered it if they knew the truth, that also renders the contract null and void.
The default arrangement in any situation is that there is no contract, no partnership, no agreement. In order to enter a contract,
both parties have to agree to
all of the terms.
When I enter a contract with someone, I have the
right to make any demand that I want ... even a demand that's completely ridiculous. When signing an employment agreement, I have the
right to insist that my boss leave a lollipop on my desk every Wednesday morning or owe me $437 each time he forgets.
And my prospective boss has the
right to tell me that he won't hire someone with that clause in the employment agreement.
Until we reach an agreement, there's
no contract.
I have the right to decide to do with my body (and my life). And I've decided that I'm not going to spend my life married to someone who is having sex with other people. Therefore, I found a wife who agrees that my view is completely reasonable.
MoonWater,
The way you phrased your statements makes you sound completely egocentric. If someone disagrees with your view on monogamy/polyamory, they have
every right to find a partner who is more compatible.
but why should such vows be taken in the first place?
If the person wants a contract badly enough, they'll agree to all sorts of demands. (Just look at the employment contracts of A-list celebrities to see what kinds of "unreasonable" demands can be catered to.) Under more normal circumstances, people are willing to agree to demands that seem fair to them. My wife and I agree to be monogamous, because the same rule applies to both of us. Both of us are too jealous to want an open relationship, so we agree to monogamy as a compromise which is fair and works for both partners.
If no such vow is explicitly taken then what's the problem? And why should the saying of such a vow be the default or be considered a requirement for a relationship.
But what if no agreement in that regard is specifically stated?
In a legal contract (including a marriage contract), the law states that undefined terms will be interpreted the way a reasonable person would normally define them.
That may be a complicated concept, so I'll break it out into a few pieces.
First of all, most contracts involve
defined terms. For example, let's say a lease agreement states that a $100 payment is made on the First Day of every Month. (Pay attention to the oddly capitalized words. That's a clue that First Day and Month have their own definitions in the section of the contract where terms are defined.) In that definitions section, a "Month" could be defined as "every seven days" and the "First Day" could be defined as "Wednesday". (It seems like a ridiculous example, but I've seen stuff that was almost as crazy in actual legal contracts.)
On the other hand,
undefined terms (anything that's not specifically defined in the contract) will have it's normal definition. If I'm in the U.S. and dealing with the U.S. branch of a company, then "$100" means 100 U.S. dollars, even if it's
not explicitly defined that way.
In most societies, reasonable people would normally assume that fidelity is part of marriage. Therefore, a court of law would rule that sex with someone other than your spouse was a violation of the marriage contract ... unless your marriage contract
explicitly stated otherwise. (You could also have an
informal agreement with your spouse that explicitly stated otherwise, but that would be harder to prove in a court of law.)
Even in a less formal relationship than marriage, the burden would be on you to explicitly explain that monogamy was not part of the relationship (or on whichever partner has an atypical view on the nature of the relationship).
This societal expectation probably goes back to early inheritance laws where men wanted to ensure that their property was inherited by their sons (and not someone else's sons). By now, it's so ingrained that most people don't consider the reasons behind it.
Does the other member of the party have any real moral right to get upset if their partner has sex with another person?
If it's a marriage, the other member has a
legal right to take you to divorce court, because you violated your legal contract (unless that contract explicitly states that it's an open relationship ... or you can prove there was an informal agreement to have an open relationship).
But I have to say, you are too hung up on morals.
Even assuming that you're just casually dating, it's a
good idea to let the other person
explicitly know where things stand.
Before I started dating my wife, I went through several exclusive relationships and a larger number of casual relationships in my social circle. My wife personally knows a number of the women I dated before her. One of those women introduced me to my wife.
Even if one of the women had made unreasonable assumptions about exclusivity (for example, assuming exclusivity on the second date), it could have hurt my reputation inside that social circle. For that reason, I was very careful to
explicitly let women know where things stood (particularly if I was about to engage in casual sex with a date). Because of that, even my ex-girlfriends told my wife that I was a great guy.
If you're dealing with a serious relationship (especially one that might become marriage), it's in your own best interest to explicitly inform your partner of your opinions, values and goals. Not just about sex. Agreeing about money and child-rearing may be just as important.
