I've been sexually attracted to most of the people I've dated. This is a plus in any relationship, but physical attraction isn't completely necessary for me to have sex with someone I'm in love with. What is necessary, or at least important to the point of consequence, is that the person I'm with must be attracted to me. The person I'm with must make me feel as if I am the only one who is capable of doing what they want/need. And this isn't a one-sided feeling. When someone makes me feel that way, I reciprocate. And even though I'm talking about sex, reciprocity is what leads to vulnerability. Knowing that you will be met at every point of openness by your significant other is what inspires more openness between two people, whether it's physical or mental. If I don't feel that potential for vulnerability in a relationship, then every aspect of the relationship becomes as clinical as patting someone down while searching for contraband. The question then becomes, "why are we together if our love has been replaced by familiarity and comfortableness?"
(Shouldn't reciprocity dictate that if a person isn't treating you well in a relationship, then you should also not treat them well either? You want to return the lack off attention they're showing you by showing them the same lack of attention? This is probably why couples stay together long after the relationship is no longer emotionally relevant - balancing out relationship karma dictates that a relationship must continue until both sides are even. When people should be thinking about walking away from a relationship, both are thinking about the zero sum conclusion of winning against the person they are with. Unfortunately, relationships are a game that have no time limit or overtime sudden death.)
I once asked a friend if I could break up with a girl because she had bad luck. He told me, "you can break up with someone whenever you want." That truth was so obvious that now no matter how hard I try, I can't not see it. It's just there. It's in the face of everyone I date. And I forget that not every one can see it. If we don't work out, then we don't work out. It doesn't matter whether or not I see the end of a relationship coming. In fact, if I can accurately call the end of a relationship, then I don't feel so dumb when it ends. It's the break-ups that come out of no where that really fuck us up. Not only do we not trust the person we loved, we don't even trust ourselves. And not being able to trust ourselves can be very difficult when we are most likely going to be spending a lot of time by ourselves for the foreseeable future. Luckily, most times we drag relationships out until the bitter end so that by the time we find ourselves single again, the only hurdle is the one of adjusting to life on the outside. This usually involves drinking or any other thing that distracts us from ourselves. Sadly, one way we deal with hurt is by creating new hurt.
When a relationship ends unexpectedly, we punish ourselves. At least when we self destruct, we're in control of that self destruction. And when we grow tired of that, we correctly mourn the end of the relationship and learn to trust ourselves again. Usually those moments come when we take a walk through an empty park, leaves falling off trees, sun setting over a hill, dogs barking and humping, and we realize how beautiful life can be, even if we are single. And then we work on taking our lives back. This process usually involves pottery or yoga class. Anything to take back life.
But then you run the risk of becoming a lifer. Someone whose whole personality is based on their relationship status. Are you a single, small dog owning bike rider. Or are you a serial dater who never brings people back home? Are you the sheepish, previously hurt individual who pushes people away and turns love into a game? Are you the person who was put through the emotional wringer too many times, and now only has the ability to date younger people because they're easier to manipulate and fall for the easy tricks? Etc. It goes on. Each single person is spunky in their own defensive way. It's that spunk that attracts us to people.
And it's not much better for couples who fall into a stagnant, tepid pool of mundane repetitiveness. These couples generally seek out other couples to hang out with because it means dealing with other people who are in the "cult" of coupledom. Also, couple dates are great for sizing up other couples, so you can get a sense of how much better you have it in your own relationship. All relationships have problems, and hanging out with problematic couples helps other couples to reassess where they are within the context of the couple world. And that's important.
We never stop completely being single or having our single opinions. And when we're in a couple, the single, autonomous person that we are us doesn't shy away from causing inner personal turmoil at the expense of the relationship. At least when we hang out with other couples, single, autonomous us is able to see the world through the 'couple lens'. And for a while, single, autonomous us can quiet down and let things be. Maybe there are other fish in the sea, but single, autonomous has seen that other fish usually come with other problems in the long run. So why move on when we have already adapted to the problems we do have?
Without other relationships to judge, couples would have less of an understanding of how good or bad they actually have it. And even if a couple has it relatively good, staying in the relationship is never a mandate. And this is why relationships can end as suddenly as they began. It's a choice.