I don't understand why you wouldn't go to Indiana with your husband either. The biggest problem that we face in our marriages is that each spouse is a married-single, going off in his/her own direction. What all of our marriages need is more time together. Time spent enjoying the family together. That's what this trip should be. And that's why you most certainly should go. If your goal is to save the marriage, you need to have as much shared time as a family as possible.
