If it makes you feel any better, my parents did something last night in regards to my recently deceased grandmothers estate which well, lets just say, is greedy and not morally ok with me. She would be rolling over in her grave. Anyway, I was so upset last night I was beside myself. We are planning a trip to DW next year with my parents. I just kept telling my husband over and over last night that I was not going on the trip with them. Well, today a calmer more forgiving me has emerged. My kids deserve to have fun with their grandparents and my parents deserve to have fun with their grandkids. These are memories they will have for the rest of their lives.
I dont know the severity of the secrets and every situation calls for a very tailored solution. That begin said, if your parents are generally good people and it is a healthy relationship for your kids to have, your kids and parents will appreciate it if you dont let your issues with your parents interfere with the relationship between them.