Because it will signal your high male mate status:
Chapter 5, “Green-Eyed Desire: From Guarding a Mate to Trading Up,” deals with other economic constraints relating to the human mating market. Women appear to use sex to help guard male mates by keeping them satisfied, reminding men what they stand to lose should they defect—or as many women in the study put it, “keep[ing] his mind off other women.” Women also seem to be motivated to sometimes have sex with other men as a way of gaining information about their mate value or to obtain a better partner—i.e., to “trade-up” in the mating market. Attracting a high-quality mate can allow a woman to enhance and evaluate her mate value, and many women cited this as a reason to have sex. The authors refer to research showing that women do this more often around ovulation.
So what does this have to do with leaving a woman’s company soon after sex? Much can be inferred from the study results in the quote above. For instance, if women use sex to keep a mate satisfied and his mind off chasing other women, then a hasty post-coitus skedaddle undermines her mate guarding efforts; she will be compelled to try even harder in the sack next time. And as I’ve noted before, a solid, healthy relationship rests on a foundation of the woman chasing the man. The day your woman succeeds at guarding you is the day you begin the slide into betahood, infrequent sex, cuckoldry, and eventual breakup.
More importantly, since women sometimes use sex with new men to enhance and evaluate their own mate value, a calculated quick departure after sex will disrupt her self-evaluative process, leading her to conclude that she isn’t as hot as she thought (which is exactly what you want her to think). While landing a charming SOB like yourself for sex will boost a girl’s ego, persuading you to linger afterward to cuddle will send her ego straight into the stratosphere. Since American women’s egos are already in the stratosphere, theirs will get propelled into distant galaxies. It’s critical that you keep a woman’s ego in check if you want to enjoy years of blissful love and sexual release.
This study, and its implications, confirms my everyday experiences. I have noticed that when I leave a chick right after sex — either directly by walking out or indirectly by nudging her out — she will text or call like a woman in love the very next day, or even later that night. The post-coitus premature exit (PCPE) is especially powerful when executed at two in the morning.
If you are at her place, many times a girl will invite you to stay for the night. She’ll couch it in plausibly deniable terms, such as “You’re welcome to stay if it’s too late for you to grab a taxi now.” If you need an excuse to drop a PCPE, just tell her you have to get up early for a business trip. If you and her are at your place instead, assume the PCPE by announcing soon after sex that you’ll be happy to walk her to her car or her home, and that she must be looking forward to sleeping in her own bed.
Whatever you do, avoid the post-coitus cuddle with a new girl who is above the average quality of girls you normally get. If you’ve had the good fortune, or expertise, to bag yourself the female equivalent of a 12 point buck, you don’t want to ruin your established high mate value and budding relationship momentum by snuggling and squeezing her tight as if she were your childhood security blanket. Post-sex cuddling is like a chemical reaction which drains your testosterone by the minute. Intimate cuddling will convince a girl to give herself high marks on her self-evaluation, and once she’s done this the odds she will see you as a worthy mate for the long haul — sexual or otherwise – drop precipitously. It’s all done on the subconscious level of course, but that’s the level that is most dangerous, since it operates by flying under the radar of our conscious perimeter defenses.
Looking at all my flings, one night stands, and relationships, the ones where I rolled over after sex and gave the girl my back, or where I got out of bed and put on my clothes to go home, were the ones I was in complete command of the direction of the romance. I never had to initiate texts or phone calls, or come up with date ideas, with those girls; they did all the legwork.