"A man who shaves his beard because his girlfriend tells him to deserves neither." Not the beard, and certainly not the woman.
If your girlfriend doesn't like your current beard it's because it needs work, not because she hates beards - even if she doesn't know it yet. It's your job to show her how much she actually loves and adores them.
Lucky for you, it isn't hard to do; after all beards are pretty loveable. First off you need to keep your beard groomed. Hairs all over the place make your beard look messy. Regardless of the beard style you have - Keep it neat. You can have a foot long beard, but you still need to trim the split end hairs and stragglers. It's also a lot easier to keep clean that way.
Another necessary step in this process is getting your beard healthy. A wise man once said, "your beard is a temple" so we must treat it as such. We all know products can be a pain in the ass, but the truth is conditioning your beard a few times a week while your taking a shower can make a huge difference - so to take a page out of Nike's book... JUST DO IT!
It's that simple really. Keep it trimmed and healthy, and instead of nagging you to cut it your girlfriend will be swimming in your beard. Stay wavy my friends.