Hello. Check out this article detailing the reasons why semen loss is harmful.

http://www.universal-tao.com/article/shorten.html

http://darwin.nmsu.edu/~molbio/mbfaculty/vanvoorhies.html

http://www.icddrb.org/images/jhpn24_4_Semen-Contains.pdf

Semen contains the bodies vital energy according to taoists who realized this thousands of years ago.
Now there has been studies published by the new york times that prove this.
I reccomend reading Taoist Secrets of Love By Mantak Chia.
or the Multi Orgasmic Male by Mantak Chia. (it talks about the study here)
You lose alot of energy, immunity, life force, well being, confidence, etc... when you ejaculate
but there are many methods that seperate ejaculation from orgasm.
many people think that if you dont ejaculate its unhealthy- totally untrue. i have not ejaculated for half a year and i have a tonnnnnnnnnn of energy, and can have sex as often as i want. and as long as i want, where before i would las very short time and come and both people would be unsatisfied.
i can tell you this is certainly untrue. its so sad the sex "education" were given in school.

its your choice wether you waste your energy, or transform it into deeper pleasure, health and love
good luck, i hope this information improves your life and relationships