As you should know, there are a lot of private things that go on in a relationship that are not and should not be discussed with the children of that relationship. I am going through the annulment process now and I pray that my children never have the opportunity to find out the grounds for this. It would shatter any relationship they had with their father. If they find out what a cruel streak their father has, it wont be from me.
My father in law got an annulment from my mil after 35 years of marriage…it didn’t change anything for my husband…my mil was really angry at him though…
Your father can apply for an annulment, but it doesn’t mean he will get one. Considering the circumstances, he may get conditions put on his annulment, blocking him from immediate re-marriage. Sometimes that happens even when an annulment is granted. It is not a guaranteed shoe-in for automatic remarriage for the petitioner.
Your mom may have kept her vows, but if your dad did not understand his, it ultimately does not reflect on her. As an adult son, you may be called as a witness, but of course you can decline to give testimony. It is a painful and time-consuming process, and serves as a great deterrent not to make the same sort of mistakes the next time around.