no after it's possible, yes, hard (pun intended) but possible.  i've pissed all over the bathroom trying to aim while hard, it is quite a feat, but right when you're about to jizz your body won't let you pee
it's possible to pee hard but not possible to pee right before you jizz, that's one of the things your prostate is for, basically three tubes come into it, the urethra and the 2 seminal tubes and the prostate joins them and opens one or the other