You would only be right if the meme was quoting her. The girlfriend could say "You don't buy me jewelry", and the boyfriend could turn around and say to his friends that she said "I don't buy her jewelry". Both are grammatically correct statements. The second statement can be taken one of two ways. Either he is not buying her any jewelry or he is buying her jewelry just not the jewelry she has. It is the latter that was used for this meme.
On another note, for someone who claims to be an "average genious", you sure do have plenty of grammar mistakes in your comment, which if we were to use the same standards you hold for the meme, then your comment has no value, taste, and makes utterly no sense to the average GENIUS.