Imagine a religious parent who's religion opposes gay practices, and he/she obeys these rules. He/she trusted Arthur and Toy Story as educational programs, and sat his/her young child down in front of those shows, only to see these sinful things. Imagine what his/her reaction would be! My mother for example, who, like me, is religious, kept these things away from me until I was a teenager, as all parents should. Children shouldn't learn about reproduction until their teen years, so the same should apply to gay marriage.
So the double standard is the existence of religious families. Religious families make up a majority of the population of mankind. Just keep these things away from kids. If you want them broadcasted, they should be rated as 12s or 15s.