[CorvusMonedula]

I think you should tell your Dad.

In my experience what mostly worries parents is the unreasonable expectation that their child will lose all their money and turn into a degenerate gambling addict who will do anything to fund their vice.

I don't know your Dad (obv) but I suspect he might be more concerned that you were keeping a secret from him.

Does your Dad ever pay money to go to sports events? Think of it like that, you're paying to play a sport and sometimes you get free tickets! Don't forget to stress that Poker is educational (on many levels, maths, psychology, emotional control...etc).

Whatever you decide good luck.