I can think of one: Gay parents pushing their social agendas onto their (likely) straight adopted children are more likely to cause self esteem and relationship issues. This isn't much different than the stereotype of the belt wielding father who tries to beat the gay out of his son.
This also reminds me of those articles in the times about 'progressive' parents raising their boys as 'gender neutral', but really, they just force them to wear girls clothes and play with dolls.
Like you I'll get modded Troll for defending you, but I won't do it anonymously. You are about half right: there _are_ people who teach gay behaviour, and it is right now not politically correct to say so because the whole issue is very sensitive to people on both sides.
I have no more problem with gays than I have with Muslims, Jews, blacks, Beiber fans, or pot smokers. Each one wants to live his life as his morals, upbringing, and internal inclination direct him. Some feel the need to preach their way of life to others, some feel the need to coerce others to live as they live, and some say "live and let live". I'm really only comfortable with that last category, the first two are sometimes problematic.
So I have no problem that my haircutter is gay, nor that two of my childhood friends were gay, nor that I have gay neighbours. I do have a problem with assuming that everyone is gay until proven otherwise, and raising children "gender neutral" through deliberately gender-confusing means. I don't buy my daughters toys, dolls or airplanes, until they _ask_ for them. They get both, dolls and airplanes, when _they_ express interest. If my baby to be born next month is a boy, he'll be _allowed_ to play with both dolls and airplanes, but he'll decide what to ask for. Just as if he were a girl. He'll _probably_ learn to prefer airplanes over dolls if he sees other boys playing with airplanes, and that's fine. He might prefer to play with girls, and he'll have two older sisters to learn from, so he'll probably express an interest in dolls as well. But none of that will come from parents' agendas.
Some people have a problem recognizing that outliers are just that: outliners. They exists, and we should treat them as we treat anybody else. But don't confuse the existence of a few outliers with the fact that the bell curve is heavily weighted towards the norm. Like it or hate it, the norm is that boys want to play with airplanes and grow up wanting to fuck women. Likewise, the norm is that girls want to play with dolls and grow up wanting to fuck men. If 0.1% or 1% or 10% of the population is gay, there is still an extreme bias towards straightness. That doesn't mean that gays are any worse than tall or short people, smart or stupid people, fat or skinny people. I wouldn't even consider then "not normal" at 0.01% of the population. But children, adopted or birthed, should not be deliberately pushed off the edges of the bell curves of normal behaivour in any of the above cases. I'm sure quite a few