The Hidden Cost of Keeping Sex Casual

November 29, 2010

One of the most valuable key economic concepts is that of opportunity cost. It’s the cost of not choosing something, the benefits left behind on the road not taken, and it’s an important component of any choice you make. Sometimes the tradeoff is obvious – if you choose to date Brad, you’re giving up the opportunity to date Jonathan, for example. Often times, though, opportunity costs can be hidden, which can lead to making irrational decisions. To show you how tricky this can be, at a recent meeting of the American Economics Association, only 22% of the professional economists surveyed correctly identified the opportunity cost in a problem.

I receive many letters from readers that ignore the opportunity costs associated with decisions, especially those involving casual sex. Here are two recent real-life Dear Susans from readers:

I. Carrie

For the last couple of months I have been hooking up with the perfect guy. He is by far the handsomest guy I’ve ever been with – he gets a lot of girls. After the first time, I figured I would never hear from him again, but he wanted to hook up again the next weekend! I’ve seen him almost every weekend since, and he seems really motivated to keep it going. He did say that he doesn’t want a girlfriend right now, and I’m cool with that. I just really like hanging out with him, and the sex is good! I’m writing because last night he went to some other girl’s sorority formal. He said he wasn’t even excited about going, but I’m sure they hooked up. I know he hasn’t technically done anything wrong, but it sucks. Now I’m worried that he will ask her to his own holiday date function. To make things even more awkward, one of his frat brothers has been acting kind of interested in me, and I have no idea what to make of that.

Carrie, there’s a lot to unpack here. Let’s break this down analytically into pros and cons:

A. PROS

Here’s what you have:

  • Ongoing late night attention from a hot guy = ego gratification
  • Good sex = libido gratification

B. CONS

Unfortunately, you also have this:

  • Fear of the potential rejection next weekend will bring
  • An explicit statement that he doesn’t want you to be his girlfriend
  • Watching him get with other girls
  • Ongoing feelings of worry that you can’t share because that’s needy and out of bounds
  • His frat brothers are not observing the bro code
  • Reputation for low standards, i.e., source of other guy’s interest is unclear, but may well be strictly sexual

In other words, considerable drama with zero emotional gratification.

C. OPPORTUNITY COST

Here’s what you may be giving up:

  • The opportunity to meet someone who would like to date you
  • A guy with less social dominance but more relationship potential
  • Someone with whom you are better matched in every way, including looks
  • Someone who will proudly tell his friends of his interest in you
  • Sex with someone who is invested in pleasing you
  • Peace of mind
  • Self-confidence

II. Katie

I met a guy last summer, and we’ve been meeting up late some nights, usually after hanging out with our own friends. At first I was really attracted to him, and I thought I might want to date him. Now I’m not so sure – it really just kind of feels like a habit. I’m fond of him but over time things have gotten pretty complicated. I don’t know any more if it’s possible to have something totally casual. We each feel things like jealousy and possessiveness, but we never talk about any positive feelings. I would really like to be in a relationship, but it’s probably not going to happen with him. I thought about fizzling it but it’s nice to have something going on in my life. I plan to end it as soon as I meet someone else, which will hopefully be soon!

A. PROS:

  • Some companionship, attention and sex, which you prefer to being alone
  • Lack of emotional investment means you won’t be heartbroken with any outcome
  • Relative safety of hooking up with one guy, provided he is also exclusive

B. CONS:

  • Relationship motivated by boredom and fear of loneliness
  • “Habit” sex rather than passionate sex
  • Emotional intimacy that is negative and destructive
  • Goal of meeting someone else to end a relationship is backwards
  • Potential to hurt your casual partner

C. OPPORTUNITY COST:

  • Being fully available now for a real, healthy relationship
  • Ability to focus on meeting new people
  • Loving sex
  • Relationship security
  • Peace of mind


Women often figure they have nothing to lose by staying in a disappointing arrangement until something better comes along. This is a terrible strategy for three reasons:

1. You are putting out the wrong vibe.

Women are rarely capable of entirely separating emotions from sex. If you’re having regular sex with someone, chances are they are on your mind some of the time. Whether those thoughts are positive or negative is irrelevant. The bottom line is that you are preoccupied.

Human beings are capable of almost limitless facial expressions and cues. Many are so subtle they are not registered consciously by the viewer. Still, they create definitive impressions. I believe that if you are having a sexual relationship with someone, it is impossible for you to send the full range of cues that signal interest and availability. By definition, any attraction you feel or encouragement you provide to another man will be compromised.

2. You are not pursuing your strategic objective.

I know several women who dated like it was their job until they found their partners. Often we must take action to get what we want. It feels better and is far more effective than passively waiting for the right person to miraculously cross our path and pursue us. One of the most common ways that people meet their life partner is through friends of friends (after school and work). It should be obvious then that your goal should be to have as many friends and acquaintances as possible, and to consistently make an effort to meet new people of both sexes.

If you are at a party texting your FWB, you are not noticing and introducing yourself to someone new. You are not networking. Even worse, you may decide to skip the party and stay home to have sex instead.

There is also the probable risk of misinformation. Your friends will in some way consider you “taken.” If someone new and interesting asks about you, they are likely to be told that you have some “thing” going on with so-and-so.

These are just two examples of how a casual involvement can sabotage your efforts to get into a relationship, but the possibilities are endless.

3. You are communicating low standards.

It’s no secret that a FWB is a hell of a lot easier to come by than a boyfriend. If your goal is a relationship, then having casual sex means settling for something substandard. It conveys a low opinion of your own worth. It also reduces the pool of potential partners, as many men will prefer a minimum of previous partners to a plethora of previous hookups.

Neither happy nor unhappy, neither loved nor despised, neither committed nor free.

Halfwaying it keeps you single.