Human Species: Built for Monogomy?

(THE OPINION)

A few days ago, while I was getting my nails “did”, I got into a slightly discouraging debate with my nail lady and two of her clients regarding couples and “forever afters”. The debate was 3 against one (one, being me). On the other team: A 34-year old married woman who we will call Rosie; a gay man who has been in a domestic partnership for 8 years (we’ll call him Tim); and then there was my nail lady (we’ll call her Jackie) who is divorced and currently living with her boyfriend and his two kids.
Tim is about 40 years old and very committed to his partner. Tim told me that he strongly believes (and always has) that no two people are meant to be together for the rest of their lives. He said that people change and grow apart. His parents have been married for 44 years and he has asked them over a dozen times to get a divorce. He said that humans are animals…and only like 2 species of animals mate with one mate for life. I argued that my parents have been married for almost 40 years and are still very much up each other’s assholes. They go everywhere together and my dad doesn’t know what to do with himself when he is without my mom. Tim merely acknowledged that as an exception to the rule. The others agreed with him that it was “unnatural” for two people to live their lives faithfully dedicated to only each other.
Yes, people do change as time goes on but, I think the best way to deal with that situation is to expect it and prepare for it so that when it comes, you recognize it and can ride it out. I think people’s feelings will rise again like a rollercoaster. If you wait, it will come again. I think it is possible to grow together and not grow apart. You also need to know and expect that the relationship will change and the kind of love will change…but you have to know that it is coming. Those who are not willing to sacrifice the type of love that you feel at the beginning of a relationship are the people who will not be able to sustain a long term relationship because they will just keep thinking they’ve fallen out of love.
Jackie and Rosie believe it goes against our nature to be with one person forever and say that is why it is so easy to stray and there is so much infidelity (even when you love someone). Difficult…it is. And sometimes, it is attempted with the wrong person. Marriage is definitely not just rainbows and butterflies. I am fully aware that it is a lot of work and effort. You must know beforehand that there will be times when you will doubt your feelings for the other person and even go through phases where you might feel like you can’t stand them. Marriage or any “forever after” requires sacrifice and a lot of compromises. You will quickly come to realize that you are not living your life just as you please anymore…there is someone else to consider now besides yourself.
I acknowledge that we, as humans, will continue to lust and have normal human thoughts. This is why it is “difficult” and requires work. The fact that it is difficult may make it seem that it is “unnatural” because it is not our natural instinct. Fine. It’s not our natural instinct but why is anyone faithful? It is not for ourselves…and it’s not because it’s our natural inclination. Commitment and loyalty is more like a meaningful gift that someone can give to the person they love to show their respect for the relationship and allowing the relationship to remain…respectable.
Thoughts? Comments?