Seeing as there are no "Real person" tagged females on here...
If I was a woman: I'd be on birth control, during a one night stand I'd probably always/usually let him decide if he wanted to go bareback or not.
I mean, speaking as a white guy, my cock has been bareback inside approx 50 women's pussies over the last 17 years, and honestly I think for probably 90% of those women I've been turned on by the thought of knocking them up during sex when I cum inside them.
Which makes me wonder, if I was woman, would I be any different? I'd be on birth control because I'd want my baby to have a loving dad or at least the financial support of one. BUT I'd also be totally turned on by the thought of getting pregnant from the casual sex. No birth control is 100% so then that "less than" 1% chance is always in the back of your mind when he cums inside your vagina.
Also, I'm 100% certain that ALL men who, if had the chance, would absolutely love to knock up another mans wife especially if her hubby had no knowledge of it, and especially (lol) if the baby came out black - which would never realistically happen unless the woman is an absolute idiot or autistic or something. But for the "other" guy the thrill is always there in the back of his mind hoping that it might happen.