You should read more YA. Try out David Levithan, Hannah Moskowitz, Ellen Wittlinger, Julie Ann Peters, etcetera. I have two gay sex scenes in one of my MS's and I've never gotten any flack from beta readers.
tbh, I don't care if you fade to black or not. I'm of the opinion that sex in any novel should build up to the BIG earth shattering scene! just after the midpoint. Unless it's important, I'd save the graphic details for then, and let the reader wait in anticipation. Some screenwriters call that sex at sixty. If you give me all the sexy details in the first half of the novel, there's nothing left for the second half. You've squeezed all the chemistry out of your couple, IMO, and they might as well be married with kids, because there's nothing left, sexual tension wise, for me to care about.