I don’t think George is gay. He wouldn’t need to have Rumple turn him straight in order to have sex with a woman. He doesn’t need to be in love with a woman to get her pregnant. Also if George could have Rumple turn him straight, why would he then be turned back when, in his view, being straight would solve the problem.
I think George did love his wife, and he loved James too. It was after his wife’s death that George became bitter, yet he WAS a good king, putting the needs of his people before his own (unlike Snow and Charming, Screwball Ninja has an essay on it). Having Charming pretending to be James must’ve been torture for George, there was a stranger wearing his beloved son’s face.