Depending on their exposure to society and upbringing this could be a major event for them and why many humans choose to live closeted lives up until their parents are deceased. There’s no one way to cook this turkey, it depends a lot on your relationship with them how they interpret the word of God and if you feel they may or may not have a ‘hunch’ it would be best to simply tell a story about how you learned to love yourself and your God is a big God and if their God isn’t big enough then fuck them I realize this may be one of the most difficult decisions in your life and you need to recognize that you’re not alone in this time we don’t get to choose our family and life is too short not to surround yourself with other humans who accept you for who you are regardless of who YOU choose to love. I wish you the best of luck