I understand what you mean, and as long as you give your opinion/view about the nature and not the people, I think it is okay.
I also am against it and don't like it, yet I have homosexual friends I like and respect. We all have family members with natures we do not like, yet we like them and care for them. I have friends who do not like Islam, really hate it too, but I don't look down on them since it is just their opinion/view about Islam.
I just ask of you to not demonize them and not state your opinion/view in a way that hurts their feelings. I think saying that you're against it is good enough. Also, I suggest keeping it a general thought without having someone specific involved, or not saying it with homosexuals around. My friends against Islam don't talk about it when I'm around and I respect them for that.