This Week in Sex is a weekly summary of news and research related to sexual behavior, sexuality education, contraception, STIs, and more.

Women Are Interested in Casual Sex Too

It has long been thought that men would be much more likely to accept an offer of sex from a stranger than women would. As Rebecca Adams of the Huffington Post explains, at least among academics, this belief is based on experiments done in 1978 and 1982 (and published in a 1989 study) in which men and women were asked one of three questions by an attractive stranger: “Would you go out tonight?” “Will you come over to my apartment?” or “Would you got to bed with me?” In those experiments, not one woman said yes to sex, while numerous men did.

Researchers in Germany, however, believe that the design of these experiments was flawed, because it didn’t take into account the real issues those women who said no might have been weighing, such as personal safety, sexual violence, and damage to their “reputations.” So they attempted to create a modern-day study that eliminated some of these risks.

The researchers gathered 60 heterosexual men and women, telling them they were testing for an online dating site. Participants were shown pictures of people of the opposite gender and told that some of the people wanted to date them and others wanted to have sex with them. Participants were left alone to decide with which of these potential partners they wanted to date or sleep with. To eliminate (or at least diminish) women’s fears for their own safety, participants were told that the first 30 minutes of any in-person encounter would be “supervised.”

The results: exactly the same proportion of men and women opted for sex. It turns out that if you create a safe environment, women really will opt for casual sex.

Rising Rates of STIs Among Arizona’s Seniors

The Arizona Department of Health Services released new statistics this month showing that sexually transmitted infections (STIs) are on the rise among what some people might see as an unlikely segment of the population—senior citizens. Statewide gonorrhea rates among those older than 55, for example, rose from 4.9 cases per 100,000 in 2012 to 6.8 cases per 100,000 people in 2013. In Maricopa County, gonorrhea rates among older adults more than doubled between 2012 and 2014, from 6.1 cases to 12.7 per 100,000.

Experts believe that a combination of factors are leading to STIs among this age group. People are living longer and staying healthy longer. This generation of older people came of age at a time when sex outside of marriage was acceptable. And men now have access to drugs like Viagra and Cialis, which help them to perform well into their later years. Plus, as sociologist Pepper Schwartz told the Arizona Daily Star, older people are taking advantage of online dating. “The fabulous thing about the Internet is they can find out who’s really out there they might never have run into otherwise,” Schwartz said.

Living longer, finding partners, and having a healthy sex life is all good news, but these seniors do not appear to be practicing safer sex. Jennifer Bass, communications director at the Kinsey Institute for Research in Sex, Gender, and Reproduction, pointed out that many people this age are coming out of decades-long relationships because of divorce or the death of a spouse. “They’ve been out of the market for quite a while. So they don’t really know about protecting themselves,” she said. “They’re not worried about becoming pregnant, but they might not think about the consequences relating to STIs.”

So maybe it’s time we turn the tables on sex education. The next time you go to visit Grandma and Grandpa in the Arizona desert, have a talk about today’s birds and the bees, and hand them a box of condoms just in case.

Two to Three Cups of Coffee a Day May Keep Erectile Dysfunction Away

A new study should have java lovers and, well, lovers, cheering, because it turns out that caffeine may be good for erections. Researchers from the University of Texas Health Science Center at Houston analyzed data from more than 3,700 men who participated in the National Health and Nutrition Examination Survey. They found that men who consumed 85 to 170 milligrams of caffeine a day were 42 percent less likely to report erectile dysfunction (ED), and men who drank 171 to 303 milligrams were 39 percent less likely to report ED, than those who drank under 7 milligrams a day. (A cup of brewed coffee has somewhere between 95 and 200 milligrams of caffeine.)

Caffeine is known to dilate blood vessels, which can increase blood flow—in this case to the penis. So go ahead and pour that second cup. Don’t like coffee? Perhaps a strong pot of tea will do the trick.