This is a rather silly thread. You're not doing anything illegal. You're playing a game.
If you're ashamed of playing Pokemon so much that you have to keep it a secret, there are bigger problems there.
I never keep it a secret. I'm 19 years old, I've been playing Pokemon since the one Christmas that I got Pokemon Blue and Red. Pikachu is my favorite Pokemon (cliche but w/e) and I have about...7 plush Pikachus in my room, and I have a Pikachu pillow pet on my bed. I take one of my Pikachu plushies with me everytime I go on vacation (which is a few times a year).
I bought a Pokemon t-shirt in my senior year of high school and wore it multiple times, and got tons of compliments from people of all shapes and sizes. Right before I went on my last cruise I bought Ashs original hat from the original series.
I wore that hat on the plane and had Pikachu sticking out of my backpack. Some lady on the plane who had younger kids and needed to pass her food to them (she wasnt sitting next to them) said "Hey Pokemon" (to which i reacted and turned around) and she said "Can you pass this to my kids please".
Was I embarassed? Not in the least.
To be honest, nerds are cool. Everyone loves nerds. To be able to freely embrace your inner geek takes a LOT of courage and confidence, and people respect that. My parents do rag on me sometimes for liking Pokemon, but that doesnt stop me from buying Pokemon stuff or watching the show or playing the game. Im in college and I was playing Pokemon black in one of my classes. I really didn't care.
In case you think im making this all up, here's a picture of me searching cerulean cave for mewtwo.
http://i51.*******.com/16bbvif.jpg
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SUPER WEIRD COINCIDENCE. When I uploaded that picture this was the ReCaptcha
http://i55.*******.com/2l7rll.png