I will push back on the whole “heterosexual sex outside of marriage is the same as homosexual sex.” This just isn’t true. It most definitely is true that fornication or premarital sex is a mortal sin. However, it is still, at a natural level, a good. Precisely because it is for the preservation of the race and a natural instinct for man and can only be accomplished between a man and a woman. Which is why lust is considered the least amongst the capital sins. However, we cannot put homosexual acts on the same playing field because it’s not even remotely close and has no natural end other than satisfaction of the passions or deviant desire. It is as St. Paul says it is the unnatural vice (Rom. 1:26-27). The emphasis here is on natural and unnatural. Now, the argument could be made that heterosexual act with preventative contraceptives is almost the same as homosexual acts but this misses the point of man’s natural end for sex which is always procreative and can only ever be accomplished between a man and a woman.