I have a new operating theory regarding relationships. It goes like this:

When you start spending a lot of time with someone, such as a friend or romantic interest, after a while you start to be so exposed to them so regularly that you begin to run the risk of falling into their sphere of influence. This can include a lot of things: Speech patterns, memories, stories, even material items like CDs and clothing can start to intermix. It’s part of what people do in order to feel close to each other.

But when you get right down to it, the most significant thing you share with people you spend a lot of time with is germs. In theory you could swap stories and emulate speech patterns from perfect strangers. You could even trade possessions with people you didn’t know very well (depending on how blindly trusting you were) and it wouldn’t really make a difference. The bigger thing is simply that these are by-products of just being in the same physical space as a person or group of people frequently.

There are even levels to this; degrees upon which you can identify, quantifiably, how close people actually are. Take kissing for example. If there is someone you kiss on the mouth, chances are that is someone you either do see quite often or someone that you would spend a lot of time with if possible. But when you consider how disgusting the act of kissing actually is when divorced from its sentimentalized, romantic cultural context you can discern that the real point of it is to say, in essence, “I’m willing to catch something from you.”

Lovers will often kiss each other in spite of colds, flus, cold sores, lip fungi, pimples, bad breath, sore throats… because ultimately they are expressing that those things are worth the risk for the sake of the other person and in fact by exchanging saliva, they actively taunt the very high probability that any germs, viruses or spreadable ailments will be passed on because they are non-verbally expressing the sentiment that “If I’m going to get sick, I want it to come from you.”

The closer you get to someone, the more risks you expose yourself and the higher the chance of contamination. This can be expanded to sex (and I’m not really talking about STDs here, more the fact that when you’re that close to someone, naked, sweaty, etc. if one person has a cold or something, the other would have to be remarkably fortunate to avoid catching it) but also scaled back for less intimate relationships. Consider how with a friend you might take a bite of their meal using their fork or try a sip of their drink from a straw they were using. If that person were another non-relative, you’d never consider such a thing. Who knows what kind of skanky scum they have happening in their mouth. But with a friend you’re able to go for it because you’re subconsciously telling them, “It’s okay if you give me cooties, buddy. I won’t hold it against you.”