Whether or not being gay is a choice, comparing it to paedophilia is wrong. Even if both were a choice, or both were not a choice, this similarity alone is not enough to compare them. Paedophilia causes serious harm to other people, so there is a genuine reason for it being illegal. It is not illegal simply because being a paedophile is/isn't a choice. Whereas even if being gay was a choice, why would that be a reason to make it illegal? Does it cause harm to others? No.
It is pretty stupid to compare two things, just because they might have one thing in common. I don't want to be in a relationship with other men, but just because I don't want to, I still respect other people's right to do so. They aren't causing a problem to me, so why should it be made illegal? I personally don't like tattoos and body piercings, but I'm not suggesting they should be illegal just because I don't like them. So quite simple really- if you don't like gay people, then don't hang around with them!