True, someone who doesn't want a child would be safest abstaining. However, a man can believe he's doing everything possible to be safe (as can women) and a pregnancy can still occur. We don't (shouldn't) tell women that if they don't want to deal with parenthood, they should just do whatever they can to not be pregnant, because once they're pregnant, they're responsible for a child. But that's what you're saying we should tell men. Which is the unfair part I'm interested in making more fair. (But I also see the problem you're pointing out.)