Especially if said someone has never actually given birth. To help explain why peeing with an erection is so hard ha! Francis Hospital in Long Island, and Jay Simhan , associate chair of the department of urology at Einstein Healthcare Network in Philadelphia help answer your burning questions. We get it, peeing with an erection is difficult — but again, not pushing-a-human-out-of-your-body hard. This not only prevents semen from going into the bladder, but it also prevents urine from passing through the urethra during an erection and ejaculation. Just keep in mind that everyone is different and not all boners are created equal, so what works for some might not work for others.