What does it suggest a guy doesn't put his wedding picture on Facebook but his girlfriend does?

[Common Sense]

Facebook is a social network that too many kids take waaaay to seriously because, like you, you try to figure out why people do and do not say, do or act like you expect them to. And, therefore, just like right now, you are trying to find some great meaning in something that you will never actually find the true answer to.

I recommend you do not use an electronic social network to get your answer, please try old fashioned face to face talking. It is not a novel idea and quite frankly, it really is the best form of communication in the world. E-communications have zero emotion, no face to face contact, no eye contact and no inflection in a "voice". All important forms of real communication. Try it.