Evolution of Sexual Intimacy

the evolution of intimacy; a look at sex and relationships over time

It may seem obvious, but sex is a pretty good thing for you and your relationship. In fact, one study found people who had sex once a week as opposed to once a month felt better than if they earned an extra £40,500 (or $50,000) a year.

Research claims we could benefit from the physical closeness between our partners and ourselves, which can help make long-term relationships happier over time.

To understand how intimacy really evolves as a relationship progresses, we surveyed 1,000 Europeans and 1,000 Americans to understand their sexual preferences over time. We asked how often they have sex, how often they orgasm, if they use sex toys, and how happy they are. Curious as to how your sexual relationship might change over time? Continue reading to see what we learned.

Sexual Speed

the length of time couples waiting to have sex by sexual orientation

Waiting to have sex in a relationship varies from person to person. For some, the moment may be sooner than later, while others may choose to wait to become intimate.

According to our survey, gay couples were more likely to engage in sex sooner than straight or bisexual couples –with 38 percent of participants identifying they waited less than a week to get physical with each other. Straight couples were the least likely to dive in within the first week, with only 18 percent having sex with their partner during the first seven days of dating.

While straight couples were the least likely to engage in sexual activity within the first week of dating, with only 18 percent initiating intimacy, another ZAVA survey revealed that a significant portion of European and American men (76%) expressed their willingness to have sex on a first date. Additionally, a considerable percentage of European women (42%) and American women (37%) were open to the possibility of a physical encounter after a successful initial date.

Straight and bisexual couples were most likely to wait between one week and a month before having sex, and straight couples were more likely to wait even longer, between one and two months (21 percent).

Even though some gay couples chose to have sex at an earlier point in a relationship, other gay respondents were the most likely to wait the longest before doing the deed. Eight percent admitted waiting more than six months before getting intimate with a new partner.

Sexual Routines

frequency of sex based on the length of people's relationships

Having sex can be good for your mental and physical health. Science has shown it can make couples happier and have a positive physical effect on the body. But who’s to say how often you should have sex in your relationship?

Our survey found regardless of how long participants were in a relationship, most people had sex two to three times a week on average.

Of course, sexual urges may be strongest in a new relationship. Those in a relationship for less than six months were the most likely to have sex more than once per day or at least once a day. That level of physical intimacy may be hard to maintain, though, as these rates decreased substantially as the length of relationship grew.

People in a relationship for 11 years or longer were the most likely to rarely have sex with their partner.

Positive Sex Vibes

percentage of people who are happy with their sex life by gender and relationship length

While some studies have shown straight women have the hardest time achieving an orgasm during sex, our survey found women were the most sexually satisfied in a new relationship.

In fact, 74 percent of women in the first six months of their relationship were satisfied with their sex life. Unfortunately, this percentage fell to 47 percent for those in a relationship between six months and a year. While women in somewhat long-term relationships saw a spike in sexual satisfaction (56 percent), women who were with their partner for four or more years were the least likely to feel satisfied with their sex life.

Men were generally less satisfied with their sex life earlier in their relationship compared to women. Just over half of men in a new relationship were happy with their sex life, while 65 percent in a relationship for six months to a year said the same. Like women, men also saw a decline in sexual fulfilment as their relationship progressed over time, but were actually less satisfied overall. While men identified being the least satisfied with their long term partners, both men and women told us that different stages of relationships and partners can be more sexually fulfilling than others.

Climax on Point

which type of partner induces the most orgasms

There are a number of reasons why men are more likely to orgasm with greater frequency than women. Our study found that men were at least 20 percent more likely to orgasm every time regardless of how old – or new – a relationship was.

One-night stands turned out to be the best for men and worst for women when it came to achieving a climax. While 64 percent of men reached an orgasm every time, only 11 percent of women said the same.

Women were significantly more likely to say they orgasm on cue when they slept with a long-term partner or spouse, but more than half of men said they peaked with a stable partner. While women were significantly less likely to orgasm across the board, science has shown women may rely less on their climax to feel satisfied during sex.

Illuminated Intercourse

lighting preferences during sex by relationship status

Research suggests having sex with the lights on can lead to better intercourse, but only single survey respondents preferred having sex in unclouded spaces.

Participants who were in a relationship or married were more likely to prefer having sex with the lights off. In fact, almost 60 percent of married people said they preferred sex in the dark.

Sensory deprivation can also be good for keeping things spicy in the bedroom, but some couples may prefer to keep the lights off to help them feel less conscious of their body or insecurities. Whatever the reason, as relationships continued, fewer people preferred having sex with the lights on.

How About a Nightcap?

people who prefer drunk se to sober sex by gender and relationship length

When it came to having a few drinks before sex, men were more likely to prefer having sex inebriated than women.

While research has shown getting a bit soused before sex can make the whole thing feel a bit a better, 48 percent of men in a new relationship said preferred getting drunk before having sex.

Almost 30 percent of women in a relationship for six months or less said the same, while 38 percent of female participants in a relationship for six months to a year preferred having sex under the influence of alcohol.

As relationships progressed, couples were less likely to prefer a drink or two before getting intimate, except women who were in a relationship for 11 years or longer. Only women in the longest relationship were more likely than men to prefer getting drunk before getting into bed.

Shall we play?

when do people introduce sex toys in a relationship by nationality

Keeping things exciting in the bedroom – especially as a relationship progresses – can take a certain amount of effort.

Of the 1,000 European and 1,000 American participants polled, 22 percent of Europeans have never introduced sex toys into their relationship, compared to just 11 percent of Americans.

For Americans, introducing sex toys was most popular after a month or two of dating. While 20 to 21 percent of those surveyed introduced sex toys into bed as soon as possible, 24 percent of Europeans and 31 percent of Americans preferred to wait a month or two before they introduced new ways to pleasure their partner.

Europeans waited a little longer before they were comfortable exploring the possibilities of sex products, with 25 percent saying they waited closer to six months. Fewer participants waited six months or longer before introducing sex toys into their intercourse routine.

When Regular Sex Doesn't Help

how frequency of sex and cheating change over time

Despite regular intimacy, not feeling sexually satisfied can be one of the primary reasons that infidelity occurs in a relationship.

Our survey found that even couples who have sex at least once a week are more likely to cheat on their partner or spouse as the relationship progresses and sexual satisfaction decreases. While couples who were in a new relationship and in which 80 percent identified themselves as sexually satisfied, 8 percent of men and 7 percent of women admitted that they had cheated on their partner.

For relationships on the other end of the spectrum, in which couples had been together for four years or more, only 65 percent said they felt sexually satisfied even though they were still having sex on a weekly basis, and 1 in 10 women admitted to us that they were unfaithful in relationships at this point.

Who Actually Cheats?

how cheating and sexual satisfaction change over time

How likely are men and women to cheat over time, especially as the satisfaction with sex decreases? Those we surveyed saw a downward slope with sex life satisfaction after one year, from nearly 60 percent to below by 50 between the second and third year. It decreases even further to below 45 percent satisfaction after the fourth year.

Men were more likely to cheat on their partners within the first year of a relationship compared with women. Though as time goes on, women were more likely to cheat between the second to third year and after four years than their male counterparts. These were when relationships saw a significant decrease in overall sexual satisfaction. While over 90 percent of Americans believe cheating is morally wrong, over 30 percent of married Americans have admitted to cheating – and perhaps sex-life satisfaction plays a part in that number.

Drunken Nights or Night Lights

how sexual satisfaction and preferences change over time

While there are many different portrayals of how sex happens in film and television – sexy nights with the lights off after a drunken night out, or a midday, cold sober spot of afternoon of delight – we all have real-life preferences. In fact, most of us don’t enjoy drunken sex. At its height, 45 percent of respondents seem to enjoy drunk sex between months six to 12 of a relationship, but the interest drops in the months that follow.

When it comes to in-the-mood lighting, it seems in the beginning and middle of a relationship, people want the lights on. Fifty-five percent of people who have been in a relationship up to six months and over 50 percent of those between two to year years approve of having some additional light during those intimate moments.

Keep the Energy and Love Alive

At ZAVA, we believe sexual intimacy shouldn’t suffer as you or your relationship age. We’re committed to helping you with all of your sex health needs quickly and conveniently.

With over 6 million patients served, ZAVA uses registered U.K. physicians and a completely confidential system to provide fast at-home delivery for many of your health needs. No need to be embarrassed, visit a doctor, or wait in line. Visit ZAVA STI's page to learn more about our sex health services today.


We surveyed 1,000 Americans and 1,000 Europeans about their experiences with relationships of different lengths and how that affected their sexual preferences over time.

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