I've always operated under the assumption that sex is considered "safe" as long as the guy is wearing a condom (because at least that means you aren't going to wake up pregnant the next morning).
But what about STDs? We know condoms don't necessarily protect you from all STDs, like herpes simplex. We also know many people unknowingly carry STDs — many STDS can be asymptomatic — and that many STDs may go unreported between partners.
According to our reader survey of 240 millennials, only less than 4 percent of men and less than 2 percent of women said that the first thing they would do if they thought they had an STD would be to tell their partner.
Let's pop the big question, then: Can you have safe sex if you and/or your partner has an STD?
It's never guaranteed that sex will be completely safe if one of you has an STD.
And one of you just might have one.
"Almost all couples are likely to have at least one member infected with HSV (1 or 2), so you probably already are having sex with someone who is positive for an STI, whether or not they are aware or have had a breakout," says Nicole Prause, PhD, sexual psychophysiologist and neuroscientist.
With certain common STDs, like chlamydia, it might just be better to wait. Dr. Nikky explains, "While chlamydia is usually relatively easy to treat, it resolves so quickly, it probably is not worth the risk just to have sex a few weeks earlier."
Other STDs, like herpes breakouts, also resolve. But because herpes can be spread from skin-to-skin contact, even using a condom might not protect you from catching the virus.
Dr. Nikky also points out the virus stays with you forever, so every time you have sex, you're putting yourself at risk for breakouts.
With extreme viruses, like Zika, however, you should just abstain entirely because the outcome of having sex with the virus could be fatal. "Some STDs are so transient, it is hard to justify having sex with an active infection. For example, Zika is sexually transmitted and can result in death and child malformations," Dr. Nikky explains.
In the end, your likelihood of catching an STD from your partner while having sex with them varies on a case-by-case basis; Dr. Nikky says it's largely a personal decision whether or not you choose to partake in sex while you have an STD.
According to her, your best bet for staying as safe as possible is for both you and your partner get tested before you have sex with each other.
That being said, you can still have fun in the bedroom in other ways.
Dr. Nikky suggests alternatives to having regular sex if you and/or your partner has an STD: "If you feel you cannot wait during an active STD infection, I would strongly recommend to redefine 'having sex' as safer sexual behaviors, like manually stroking your partner's genitals or exploring other fun sex play you might have put off when intercourse was available."
But if you do want to go all out and have sexual intercourse, she says to try using a female condom in addition to using a male condom. Female condoms cover the area right around the genitals, which helps to reduce your risk of contracting an STD from your partner.
If both partners have the same STD and have sex, that doesn't necessarily mean they're both safe.
It turns out there are different strains of the same STDs. This means if you choose to have sex with your partner who has the same STD that you have, you can still catch a different strain of the same STD from your partner.
"Not only might you become co-infected with their strain, too, but you could prolong each others' recovery by reinfection, even if the strains were similar," Dr. Nikky explains. She also points out that you should be especially informed of your and your partner's strains if you both test positive for HIV.
If you or your partner believe you're experiencing symptoms of an STD, always consult a doctor to confirm. From there, you should inform each other about your most up-to-date sexual health, so you can both have a healthy and fulfilling sex life.
Read more from our Sex Ed series.