I don't see where any of those words exclude people who happen to be siblings.
That's a pretty limited definition, but I'll go with it.what is the definition of a family?
a family consists of a brother/sister/mother/father.
If you see a couple walking down the road holding hands, you can tell whether or not they have sex? You can see that just by looking at them, can you?how do I know the difference between a brother and a sister and two lovers just by looking at them?
lovers enjoy sex.
a brother and a sister enjoy a family bond. they do not have sex.
So, what if your father had a child you didn't know about. And one day, without knowing, you met this person. Are you saying that you would somehow, instinctively know that you are related, or are somehow unable to have sex with this person because you are siblings? What if you fell in love, neither of you knowing that you were related? Or do you think somehow that such a thing is just not possible?in order for me to be able to tell a brother from a lover I need to use sex to separate them.
sibblings do not have sex.
lovers do.
My point is that you cannot. The fact that the word "incest" exists implies that relatives do in fact have sex.how else would you differentiate between the two?
Siblings are children of the same parents.
Lovers are two individuals in a sexual relationship.
The two are not, by those definitions, mutually exclusive.
Any other characteristics are not part of the definition, but a description of what you think the relationship entails. The terms you have laid out are your own set of characteristics, and are not implied by virtue of the relationships themselves.
The notion that relatives do not engage in sexual relationships is based on your own observations, experiences, or assumptions. It is not, a priori, a part of the linguistic definition of a sibling or relative.
If you want to get technical, the word "relative" actually includes people who are married. Married couples typically have sex. They are both family, and lovers. How does that suit your definition?