You can generally give your money to anyone you like.Again a law can be passed that says you can give your money to anyone you feel like. Why glorify homosexuality?
But in the U.S. you can leave an unlimited amount of assets to your spouse tax free.
If the person you want to leave the assets to is not legally recognized as your spouse, there might be a tax on it.
“Spouse” status also comes into play with Social Security benefits and Medicaid.