S.S.
There are pluses and minuses to all names. I agree that it does show to some degree that the parents aren't taking this in a very mature way, however, NONE OF US really knew what we were getting ourselves into until we actually had our own kids!! I mean, I was 24 when I had my first son and I'm only 27 now, and I still feel immature and incapable at times! On another note, our second son is named Shade and we get compliments on it all the time, and even if we didn't, I'd still love it because I knew that was what God picked for him. So if they are gonna have odd names, at least they won't be the 10th S. in second grade (like I was).
This may be an opportunity for you to learn how to let teh parents make their own decisions, as well as your son and girlfriend learning that maybe their elders really do know a thing or two!