But a word of caution if you do decide to make his green card the issue: the authorities might come after you for implied complicity.
A question for you, and forgive me for possibly projecting. Because I could see myself asking the same question at your age. The question is why you would embark on something so personal for your parents? If it's something you really want to do, that's A-OK. Just be careful to own what you want to do and not for any other reason. Trust me, it's no easier to do when you're 40 or 50 so you might as well get practice having the kind of life that you want for yourself.
A Catholic annulment is a whole different issue. I went that route, and although it was healing, it was really painful as well.
Hopefully this article helps you decide for yourself.
Hugs,
Betsey
"There are only 2 ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle."