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

Apps Like Grindr Linked to Higher STD Rates

Hook-up apps like Grindr have been around for a number of years and have millions of users, but they may be riskier than picking someone up in person. New research conducted by epidemiologists from the Los Angeles LGBT Center, the University of California Los Angeles, and the LA Department of Public Health found higher rates of some sexually transmitted infections (STIs) among men who met through apps like Grindr than those who met “IRL.”

The study, published in Sexually Transmitted Infections, included 7,184 gay and bisexual men who sought services at a sexual health center in the city between 2011 and 2013. All men said they were HIV-negative when they checked in at the clinic.

The men were asked where they met sex partners and then were tested for a variety of STIs. The study found that those who met sex partners on apps like Grindr had a 25 percent greater incidence of chlamydia and a 37 percent greater incidence of gonorrhea than those who met men in person at a bar, club, gym, private sex party, or even an online dating site. There was no difference in HIV rates or syphilis rates based on where men met.

The study’s lead author, Matthew Beymer, told the Daily Beast that there might be a relationship between the apps and HIV but that the clinic diagnoses far fewer cases of HIV each month than of chlamydia and gonorrhea, so the pattern might just not have emerged during the study period.

The researchers were not surprised by the findings; they noted that previous research shows men who met online are more likely to engage in riskier behavior—such as unprotected anal sex—than men who met in person.

There are more than 2 million Grindr users in the United States, and other apps like Scruff, Jack’d, Hornet, and MISTER are offering the same services. (There are also apps like Tinder aimed at heterosexuals.) The researchers make it clear that they are not suggesting that men stop using the apps—they just want them to be aware and cautious. Beymer told the Daily Beast, “We just want to educate individuals who may use these apps that while these apps provide numerous benefits for meeting others, they also carry potential risks that bear mentioning. We merely want gay and bisexual men to love carefully and love safely.”

Hundreds of Thousands of People Have Chlamydia and Don’t Know It

Research by the Centers for Disease Control and Prevention (CDC) presented earlier this month at the STD Prevention Conference in Atlanta suggests that hundreds of thousands of cases of chlamydia go undiagnosed each year. For this analysis, researchers looked at data from the National Health and Nutrition Examination Survey from between 2007 and 2012 and found that 1.7 percent of men and women ages 14 to 39 have chlamydia, which works out to about 1.8 million infections each year in the United States. There are 1.4 million cases reported to the CDC each year. (As a reportable disease, all diagnoses of chlamydia must be reported to the CDC.) Simple math, therefore, suggests that there are 400,000 people each year who have chlamydia but are not diagnosed.

Chlamydia is a very common bacterial STI. If caught, it can be easily cured with antibiotics. Untreated chlamydia, however, can lead to pelvic inflammatory disease, which can in turn cause scarring in a woman’s fallopian tubes and lead to infertility. The CDC recommends sexually active women 25 or younger be screened for chlamydia each year, as should pregnant women and men who have sex with men.

Embarrassed to Buy Condoms? Let Someone Do it for You

An entrepreneur in Saskatoon, Saskatchewan, wants to help locals buy all of those things that they might be too embarrassed to buy themselves. He posted an ad in the local paper offering to purchase embarrassing personal items like condoms, pregnancy tests, stool softeners, or hemorrhoid treatments. He says his idea was born out of a trip to the pharmacy during which he was embarrassed to buy Preparation H; he thought it would be nice if someone could have done it for him.

So far, more than 1,500 people have viewed his ad, but no one has taken him up on his offer. Maybe Canadians are more mature than he thought, or maybe they’ve just discovered online pharmacies.

Bears, Captivity, and Oral Sex, Oh My!

Researchers in Poland recently published a study based on observations of two male bears who engaged in more than 28 acts of oral sex. The bears are not related but both were orphaned shortly after their birth in 2003 and have lived in a sanctuary in Croatia since then. Researcher observed the bears for 116 hours and found that the smaller bear frequently approached the larger bear offering fellatio. In all of the acts, the giver would approach the receiver while he was resting on his side or with part of his abdomen exposed. If his penis was not exposed, the giver would nuzzle the receiver until he spread his legs. Each act lasted between one and four minutes and appeared to end with orgasm.

If the bears were human we’d just say they were having a good time, but this is the first time recurrent incidents of oral sex have been observed in bears living in well-maintained facilities. (Apparently, some bears kept in substandard conditions have been seen engaging in auto-fellatio or other forms of masturbation.) The scientists have a theory—other than pleasure—as to why these bears do this so often (28 acts in 116 hours means an average of one bear blow job ever four hours): They believe that the giver was weaned too early and is finding a substitute of suckling behavior. To support this theory, they note that the giver initiates every act and does not have an orgasm himself. Or, they say, it could just be a fluke of growing up in captivity.

Of course, couldn’t it also be that it just feels good?