It occurs to me that the "we both forgot to use condoms" thing that comes up often enough is a bit like suggesting that a person forgot to wear pants.
For a whole day.
And didn't notice.
Life has scripts. Little socially-agreed plays that we enact rather than trying to figure out all our interactions from scratch every time. Many of them are very simple. There's also scripts for sex. Unfortunately, the most common script out there is terrible.
Asexuality saved my sex life. No, seriously -- I mean that. I will declare it from the middle of a courtroom, with one hand on Our Bodies, Ourselves. Asexuality, as much as sex-positive feminism and far more than any amount of "hon, you just need to get laid already," helped me to access a confident, positive, and excited relationship with my sexual self.