For quite some time, I have pondered the effective difference between being a "friend" and being a "significant other".
On the face of things, one would be tempted to believe that the main difference is that significant others have some measure of territorial rights to the affectionate and sexual exploration of their partner's body.
However, the existence of Fuck Buddies and the like would seem to give lie to this principle, not to mention those exploratory periods of college existence which demand weekend orgies and the obligatory bribing/inviting of the RA.
I have begun to think, over time, that perhaps it is more important to define what makes a good friend than what makes a good SO, seeing, as I am, more and more couples break up over time, and in more and more spectacular fashion, based greatly on a lack of congruent views of what makes up a relationship.
Generally, with reference to a true, long lasting friendship, you're looking to find somebody who you can share identity with, who you can fit in with, who you continue to be interested in being with even when neither of you terribly like each other for whatever reason, etc. I.e., Compatibility.
Relationships, on the other hand, seem to be based on appearances, noticing that somebody seems cool, crushes, etc. The desire for sex, for affection, for status, etc. In fact, to a large degree, that which is accomplished on a fairly wide degree by finding a significant other would seem to be the direct opposite of that which is sought in a friend.
Real friends are people you can say anything to...including fairly insulting, ideologically destroying things...and they'll accept them as coming from you, and deal with them in that context. Some of them will even help you bury bodies.
Significant others, on the other hand, will fly off the handle about territorial and ideological issues, try to change you to fit an ideal that they feel you should live up to, or destroy your ego and identity based soley on your secret, perverted love of disco.
You Philistine.
It would seem, honestly, that one would actually want to spend one's life with a friend, rather than a significant other, if it weren't for that sex thing, in fact. Or, perhaps more honestly, affection. The ability to look into the eyes of another person and know that their focus, as they look back, is on you and how you fit into their lives, rather than how they'd look in an Elvis costume.
Which brings us to ask...where is the line drawn on how far one can safely go, in terms of affection, with a friend without devaluing them as such?
This is likely a cultural, or regional, question...but still, most friendship seems to be limited to handshakes, occasional hugs, etc. Cuddles, kisses on the lips, etc. seem linked mainly to the status of being a significant other, based at least partially on the assumption that the person kissing, holding, stroking you back has more than merely their own satisfaction in mind.
Actually, forget that. Settle for, they are focused on doing those things with you, and it means more than any other random stranger. Though perhaps not as much as that person they're cheating on you with this week.
Friends, it seems, are incapable of "cheating", save in that they spend time with somebody else more than you are used to them spending with you, and thus closing you out of some portion of their/your lives/life.
Never mind the difference between velcro couples, solid 40 year old marriages, abusive relationships where the wife/ girlfriend cowers in the kitchen while the husband/boyfriend goes out and gets drunk enough to come back and show her what she's really worth...
What, exactly, are we really looking for with a significant other? Love? Security? Understanding? A tax shelter? An object for the vengeance we feel our parents deserve, but will never have the bravery to face them about? A project to be changed?
What are we looking for in friendship? Shallow buddies to make us feel needed? Interaction and conversation on a meaningful, two way level? Comrades to help us bury all of the members of ABBA once we hunt them down and...oh.
The mystery continues... | 
