Rainbow kisses are likely to seem like a strange act if you and your partner aren't into sex acts, those who may be interested in performing one themselves should be mindful of the fact that exchanging bodily fluids as part of sex comes with some risks.

Some doctors, and particularly one on Twitter, have encouraged people not to perform the act at all. Others, though, suggest that it's possible to perform one safely, as long as you take certain precautions.

"Semen and period blood can carry lots of different infectious particles, such as HIV, syphilis, and hepatitis," ob-gyn Heather Irobunda, MD told Cosmopolitan. "If you are unsure of your partner's STD status, you should not be sharing rainbow kisses."

What's more, doctors suggest that one test or infrequent testing is not enough. Regular testing is necessary to ensure that acts like rainbow kisses are safe.