Because, Christine, he's the God of Mischief, a liar, and a war criminal. Those three things are normally a large warning signal to most people.
This is a secret that I am comfortable letting you know, since I trust you. I've magically binded an Infinity Stone that's a source of gamma radiation into his dimensional storage space, and Thor is acting as the key to that lock. It's the only thing keeping him compliant. And you are one of the few close links to me, that it counts as a vulnerability for someone like him to exploit.
And I hate pointing out that goats are still slaughtered and eaten in much of the world, so their quality of life is debatable.