How To Decide If It's A Good Idea To Date Your Sister's Friends: A Formula

I've never personally dated one of my sister's friends. She is five years younger than me so the difference in age has long been prohibitive. But as one gets older, the significance of age disparities in matters of the heart tends to decrease. Having just enjoyed my twenty-fifth birthday, I feel as though I may soon be entering a golden age of dating my sister's friends wherein such romantic couplings will not only be eminently enjoyable, but also socially acceptable, and perhaps even mentally fulfilling.

To prepare myself for the host of dating opportunities likely to present themselves in the coming years, I have developed a practical formula that will objectively determine whether a prospective partner would be worth the inevitable tribulations that would accompany such a union.

But before we delve too deeply into solutions, we must first identify the problems inherent in dating one's sister's friends. The main difficulty that I can identify is maintaining the brother/sister relationship in light of anything that may occur during the courtship of her friend. Obviously, maintaining this relationship will be of paramount importance if one expects to date any more of one's sister's friends in the future. Also, were the sister to become angry about something the brother did during the relationship, that brother would have two angry women to deal with rather than just one.

It is at this point that many people decide that dating their sister's friends is not a viable option. After all, it is difficult enough to keep one woman happy with a relationship, but to keep two women happy with a relationship is a Herculean feat that all but the hardiest of Mormons have neither the fortitude nor inclination to attempt. But we here at yesyesitis.com* are never ones to shy away from a challenge,** and we believe that we have developed an actionable solution that can work for you.

Let's say that you have taken the plunge and have decided to begin dating one of your sister's friends. Since your sister and this friend are both females and are friends, they will talk about their relationships incessantly with each other. This spells trouble for you. Since one of your major goals is keeping your sister happy with the relationship, and since there are bound to be bumps in the road on the way, you must control the flow of information that your sister receives about the relationship. Normally when you date a girl, you must be completely on point for one to two months before you start gradually acting like an asshole and decreasing dinner date frequency. The key to dating a girl that is good friends with your sister is to extend your on point period until you can thoroughly control the information flow to your sister.

But if your sister and this girl are friends, how can you ever control the information flow? The answer may be easier than you think. The natural assumption is that you have to become better friends with this girl than she is with your sister so that she is more loyal to you and won't share anything that you don't want her to share. This view is shortsighted. You don't ever necessarily have to make this girl like you more than she likes your sister, you merely have to make her like the relationship more than she likes your sister. This shouldn't take too much time; it is a well known fact that all women value a good romantic relationship more than any friendship they may have with their girl friends and will choose to nurture the former over the latter.*** The key is figuring out exactly how much more.

I postulate conservatively that, to any woman, one month of a good romantic relationship is worth 3 months of good friendship with one of her girl friends. In other words, a girl will choose a boyfriend of 6 months over a good friend of a year and a half, a boyfriend of 12 months over a good friend of three years, and so on.

Represented formulaically:

t = n/3

where n is the number of months the girl in question and your sister have been good friends and t is the amount of dating time in months that you will have to be on your best behavior.

Once your time table is set, you need only determine if your sister's friend is worth the amount of good behavior months you will have to log. Your willingness to log good behavior months is directly proportional to how desirable this girl is. The girl's desirability is of course directly proportional to how physically attractive she is and is also partially dependent on a host of other less important factors.

So, we need to create a "Desirability Index" to numerically represent the desirability of any given girl. Start by ranking her physical attractiveness on a standard 1-10 scale. Then do the same for an aggregate of all other factors that may make her desirable (sense of humor, down-to-earthiness, willingness to watch you get high and play video games with your friends on a Saturday night instead of going out, etc.). This will leave you with two numbers between 1 and 10. Once you have these numbers, decide percentage-wise how much each of them contribute to your overall level of interest in a given girl. If you are a superficial person, physical attractiveness may make up 70% of your interest level while everything else accounts for only 30%. If you are a dork, the reverse may be true. We will call these two percentages the superficiality coefficient and the x-factor coefficient; they will give you a more accurate view of just how desirable this girl is to you personally.

Here is the Desirability Index represented formulaically:

d = a(y) + b(x)

where y is your 1-10 ranking of her physical attractiveness, x is your 1-10 ranking of whatever other x-factors may contribute to her desirability, a is your personal superficiality coefficient, and b is your x-factor coefficient. d is a 1-10 numerical representation of her overall desirability to you personally.

This may be a bit confusing, so let's go through an example. Let's say I meet a girl and she's a stone-cold nine in terms of physical attractiveness. Unfortunately, her ringtone is "Rockstar" by Nickelback, she says things like "I just don't get Curb Your Enthusiasm", and only eats one or two bites of her entree when she goes out to dinner. Her x-factor is a 3. Now, I am a deeply shallow person, so physical attractiveness is of the utmost importance to me. In fact, it counts for 83% of why I like any given girl; everything else makes up about 17%. All our variables are now accounted for, so we can calculate my interest level in this girl thusly:

d = .83(9) + .17(3) d = 7.47 + .51 d = 7.98

As you can see a 9 who is dumber than a bag hammers only gets dropped down to a 7.98 in my book, so we're probably good to move forward. Now all we need to do is combine our two equations by determining how many months of good behavior each point of desirability is worth. I say 1.5.**** You may want to come up with a different number based on your tolerance for being on your best behavior. In our example, I've rated this girl a 7.98, which means that I am willing to put in no more than a year of being on my best behavior.

Now let's compare that number to our first equation. Let's say our extremely good-looking but slightly mentally challenged girl has been good friends with my sister for three and a half years, or 42 months. That means I'll have to be completely on point for 14 months before I reach the zone where I can ease up. If I slack off before 14 months, I run the risk of not only screwing up my chances with this particular girl, but also pissing off my sister, which will make her less likely to set me up with her hot friends in the future.

So, I'm personally only willing to put in 11.97 months of good behavior for a 7.98 girl, but I'll need to wait 14 months before I can risk slacking off. According to our equations, I should not date this girl. The amount of time it will take to get into the slack off zone is greater than the amount of time I'm willing to put in according to this girl's Desirability Index. It is way more headache than it's actually worth.

Our final formula:

If t > 1.5d ; do not date

I hope that you find our formulas effective in helping you sort out your romantic endeavors. Anytime you can boil down the essence of human emotion and affect into a couple simple mathematical equations, you really have to do it. Until next time, thanks for reading yesyesitis.com.

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*We now own the yesyesitis.com domain, by the way. No need to go through the blogspot middleman anymore when typing in our address.

**Plus, we're going through a bit of a dry spell now and are open to new avenues.

***This is one of the most salient differences between women and most men.
**** Of course, if we use this number, it means that, since a perfect 10 is the best desirability score a girl can get, then there is not a woman on earth who is worth more than 15 months of good dating behavior.
***** I think this is fairly accurate.
***** That's right. Not even you, Jessica Biel!