Peeing with a boner is more difficult than giving birth. Giving birth is definitely more painful, but pain by itself does not make something difficult. For example, putting my hand in a fire is not difficult, but it would hurt a lot. In order for something to be difficult, there has to be some chance of failure due to lack of skill, practice, or technique. Peeing with a boner often requires creative problem solving skills, especially in small spaces. There is no creative problem solving aspect of giving birth. Additionally, the way humans have evolved for these two actions supports my point. Giving birth is a natural process, which humans have evolved to be able to do. The female body is literally designed so that it can give birth with the lowest possible chance of error. The only real error that can happen is a miscarriage, which is also a natural occurrence, not a failure that occurs due to a lack of skill in giving birth. The male body, on the other hand, has evolved specifically so that peeing with a boner is very difficult. The only purpose for having a boner is to impregnate a woman, so the male body evolved to prevent urination during sex. On top of the difficulty in simply getting the pee to flow, there's the issue of actually positioning yourself so that the boner is pointing into the toilet bowl (urinals are much easier, but not always an option). In the past, I have had to give up and wait until my boner goes away because it was simply too difficult to actually pee in the toilet. There has never been a case where a woman has tried to give birth after being pregnant for nine months, not been able to do it, and said "♥♥♥♥ it" and waited 3 more months to try again because it would be easier the second try. Giving birth happens, every single time, because it's a natural process - peeing with a boner is the opposite.