Gembo you're only a few years older. Don't be so quick to judge him just on his age. He is a Bully fan and he seems to know how the internet works, so I'm sure he knows what people are like already.
Enjoy your stay, ignore anyone that criticizes your age. What really should matter is your personality, and so far you already seem a lot more friendly than Gembo despite him being older than you. Well, I shouldn't bash Gembo, he's usually a good guy, but I'm kind of disappointed to see him jumping on you just because you're a bit younger.