Can semen build up and cause medical problems if a person gets no sexual release through sex or masturbation?

If I remember correctly, excess fluid produced by the seminal gland leaks out into the urethra and is expelled along with urine, a bit like an internal overflow. I guess like all glands, if the exit becomes blocked you're going to get problems! (http://en.wikipedia.org/wiki/Seminal_vesicle)

My Fiance says that I can get moody after several days without a release. I usually don't like to masturbate by myself and try to wait for when she's in the mood. Sometimes I get that feeling before she does, but I try to hold up as best I can.

I had this problem too i think :( When i pee semen shoots out of my penis every since then look like i can't get an erection :'(

You need you Masturbate so that there isn't a build-up of seminal fluid within your body. In mose cases us men have Wet-Dreams, where the body gets rid of the old semen to make room for the new. But with
Masturbation You can not only learn to prolong your ejaculation,so as to be a better lover,But with the Start-Stop Hand-Method of bringing yourself as close to ejaculation, six times during each session,then stoping just before you ejaculate. You'll learn to control your penis,not have it control you.Most early Ejaculators have taught themselves to come PDQ, long before a woman's body has sexually warmed-up yet,then they wonder why they can't maintain their erections long enough to bring her to an orgasm. So do Mastutbate,It's good for you,much better than wet-dreams,and an enjoyable way of getting rid of normal,built up Physical and emotional tension.