In the USMC, facial hair is not a common thing among officers and not even that common with the enlisted Marines. Here is what Terminal Lance (an online comic about enlisted life in the USMC - sort of a modern day, more R-Rated Willie and Joe) has to say about it:
Now, this is take nothing away from yours or anyone elses facial hair it is only a commentary on the mustaches you end up with when you follow the USMC facial hair grooming standards.
"The face will be clean-shaven, except that a mustache may be worn. When worn, the mustache will be neatly trimmed and must be
contained within the lines of B-B', C-C', D-D' and the margin area of the upper lip, as shown in figures 1-1 and 1-2. The individual length of a mustache hair fully extended must not exceed 1/2 inch."
I grew out my facial hair when I was in college for a couple of weeks before it was just too itchy and I had to get rid of it. I'll scan some of the pictures if I find them. That will be a big laugh for everyone used to my current Marine countenance!