All current forms of birth control can fail. Anytime a fertile woman has vaginal sex with a fertile man's penis, it can result in pregnancy.
The only thing current contraception does is lower the ODDS of pregnancy happening, but doesn't prevent pregnancy from happening EVER.
Which is why if you are a sperm owner, your decision begins and ends with "do I allow a uterus owner the gift of my sperm so they can decide if I become a parent or not?", because ALL vaginal sex with your penis can result in a pregnancy. (if you and they are fertile)