Leviticus 20:13 actually means no butt stuff with women and no vaginal stuff with men. It also originally intended missionary only for man on woman and saving doggy style for man on man, but as long as you don’t have overlapping sexual acts and positions for the straight stuff and the gay stuff you are in the clear.
It’s a continuation of the whole “no mixed fabrics” thing and is part of God’s autism expression along with foods not touching on the plate.
Exactly! Leviticus is Old Testament, and there is nothing more integral to the Torah than rules lawyering whatever God says.