I read an article about a dance studio that refuse homosexual couples, mostly because they think the other learners don't want to dance with someone from their own gender. The chairman of the board says "We are unsure as to whether other students think it's fun to dance with someone of the same sex". The catch though, they haven't actually asked the participants.
The board decided three years ago that homosexual couples weren't welcome and I quote the chairman of the board: "It has worked well until now". No it hasn't, someone just haven't called you out on it until now. In reality, you have discriminated people solely on their sexual orientation, which is against the law.
I don't understand why they don't start another group which is LGBTQ friendly and let people decide for themselves. If the person want it the traditional way (only male-female) then they will sign up to the other dance class where they can switch partner without the fear of dancing with the same gender.
Why make it harder than it is?
Note: When learning to dance they, as many other dance schools, make the learners switch partners regularly. I don't think (hope not) it would've been much of a fuss if it was dancing with your partner only kind of class.
Source: Aftonbladet (Swedish article)