Wiktionary
n. 1 Sexual activity without protection from sexually transmitted disease; sex that is not safe sex, or activity considered barebacking 2 sexual intercourse without protection from pregnancy; non-use of birth control 3 Sexual intercourse without protection from sexual transmission of an allergen or teratogen
Usage examples of "unprotected sex".
That's good news, but don't let that possibility encourage you to have unprotected sex.
Our kind retreated from the world entirely, and from that day to this, any unprotected sex between our races has been forbidden, to prevent such tragedy from ever happening again.
Probably not, no more than every woman who had unprotected sex got pregnant.
Tabitha brushed a hand over her own belly, remembering for the first time what their unprotected sex might lead to.
Except there was a minority who seemed to think unprotected sex increased the risk of potential infection to the baby.