As she says, “Just because animals do certain things doesn’t prove that we necessarily do them too.” But sometimes humans can be compared to other animals, and the comparisons have weight. We might be able to get some good ideas from them.
She points out that animals flirt, they masturbate, they watch other animals express their sexuality, even through video.
They exhibit habits other than monogamy. They are polygamous and polygynous. And they are social monogamists as well as serial monogamists, even swans. Bonobos, for example, have multiple sexual partners at any given time in their life. And some species even engage in group sex. When red-sided garter snakes mate, the female is made the center of what is called a mating ball, where 100 males all attempt to mate with the female at the same time.
People exhibit habits other than monogamy. Although not always socially accepted, people partner in a variety of ways. Many of those ways have proved to be perfectly healthy.
Also,
They are homosexual as well as heterosexual. Marine birds, mammals, monkeys, great apes, dolphins, penguins, cattle, bonobos and rams are just a few of the many animal species in which scientists have observed homosexual behavior.
Humans are homosexual as well as heterosexual, obviously. And each is perfectly normal and absolutely biological. Once again, the only issue in human society is our lack of acceptance of both orientations.
She goes on to note that some animals have sex for pleasure, some will seek out additional sex partners if the current one is not interested in another session at that time, some over-indulge, and there are female initiators. And I’ll add that anyone who has had closely related hamsters can verify that some animals engage in consanguineous sex.
Consenting adults should have their rights to any of these things, without the law interfering.