I would argue that it isn't different, but I'd rather not open up that can of worms
And I wasn't picking out homosexuality or sexuality specifically - various religions teach intolerance of many things (lifestyles, behaviour, world view...), and so do other structures like society or culture one belongs to, (religion isn't the only thing that does this!). But when we're faced with beliefs conflicting with our own view, it can be temping to think we have the automatic right to 'set the other person straight' and make them think like we do.
I'm all for a good debate, letting people know my views on things, if the situation is appropriate - but with children it gets complicated, because they are under the care of their parents and not ours. It doesn't mean we can't talk to them and let them know our views on the world, it just means we need to be more careful, and to think about the ethical issues.