Well I expect homosexuality to be accepted in the churches a lot sooner than polyamory, but hey the point is, a lot of the churches do seem to be moving in the right direction.
I've many friends who (unlike me) are still in the church, even many who have serious doubts and questions about various things. They've kind of taken it upon themselves to try to help improve the church from within, which I can only admire. I'm not nearly as strong/confident a person as they are.
Nothing wrong with keeping the poly stuff low-key with the parents, and hey if that helps them gradually make peace with it, that's all the better.
All that said, it's true that Solomon had an awful lot of wives.
He must have had a full calendar ...