I just got done saying bestiality is immoral because it causes harm and can be considered to cause harm 100% of the time. As for the other two, let me get this through your thick head.

Nothing that does not encroach on another's freedom of choice (i.e., unwanted harm) is immoral. In fact, NOTHING has any inherent meaning at all. I find it amusing that I'm having to explain this to a Rick and Morty fan.

Look, man. If you want to fuck your cousin, just don't have any babies. That would be crossing the line unless you're going to get them genetically tested and terminate if necessary. Apart from that, I have zero desire to tell any other conscious being what and what not to do. Just don't cause harm.

Again, this is a well-documented philosophy and I would encourage you to pick up a book on the subject. I never had much use for philosophy books myself, having come to these realizations at an early age. And I didn't care for the one class I toom in college. But as I understand, people have whole schools of thought on this topic that agree with my own. We do have to chose some agreed-upon moral norms. But you need to understand that they are ALL made up by other humans. I chose to run with the minimal harm approach because it makes the most sense. Barring hypothetical situations involving train track switches, I'll never deviate from these principles.