No. It's not. And if you worry about your kid "turning gay," please don't.
Sexuality is complex. It's certainly not the either/or, choice/born-this-way matter it's made out to be in mainstream conversations. Scientists and keen social observers are constantly adding to the dialogue. But as far as any of us are concerned, gayness has always been a thing, it's not something anyone should be forced to hide or change, and we all have a right to be happy.
So if you're a parent of a gay kid who's trying to find a good way to open up the conversation, start with what you already know: He/She is your child, whom you love very much, and whom you want to be happy.
With that as your guide, everything should shake out just fine.
For extended commentary on the list above, check out this post by Dannielle Owens-Reid and Kristin Russo, co-founders of the Parents Project and co-authors of "This Is a Book for Parents of Gay Kids."