20 % ? You should stop buying recycled paper condoms. Most often I've seen failure rate between 1 and 5 %, which seems more realistic but still too much to handle. In fact, if I'm going to have a long-term, multi-decades relationship with someone, I'm not going to accept anything higher that 0%. The idea that I'm gambling my live everytime I'm having sex, even if the individual intercourse risks are fairly low, would ruin sex for me.