Thank you... its proving to be an educational night.
Actually, thinking about it, I’m not sure acceptance of a Homosexual lifestyle as “ok” is actually heresy. I personally would argue it’s wrong, (as I think the majority of Christians would) but I dont think it actually contravenes any of the creeds.
There is no doubt about the idea of accepting there are other ways to God than through Christ Jesus and Him alone. That quite definitely is heresy.