I don't want to risk ruining a good family relationship.

My dad and I have a WONDERFUL relationship. He's more like my best friend/brother than a father. He's always been there for me and has always treated me as an equal. The 'problem' though is that he has become increasingly more theistic. We're Hindus and I've been raised one but due to recent problems (and rational thinking) I've become an atheist. But as my 'religousness' decreased my Dad's has increased. We're going to the temple a LOT more frequently now and spending an unnecessary time there. And when we're there I have to put up with the irrational rantings of the priests too. Whenever I'm there it takes all my self-control not to point out every single mistake in what they believe in. But I've held back. Why? Because I don't want to ruin the relationship I have with my Dad. I'm scared that revealing my beliefs to him will cause an irreparable rift between us. But I'm also getting tired of going to the temple. So what should I do? Risk my relationship with my Dad and tell him how I feel or deal with our weekly trips to the temple and just let him believe that I am still a Hindu. I realize the second option is the safest, but I would really appreciate your input.

Tl;Dr: I am atheist but scared to tell my Dad because I don't want to risk our awesome relationship.