Yes, I kind of thought the visit would reinforce the warmth and happiness they find at home. Let me just tell you a little bit of my life story. I was adopted as an infant. When I was about 27 years old, I found my birth parents. I was reunited for the first time. Although I was happy to finely get to know who my birthparents were, I found out that they were alcoholics. The environment I would have been raised in would have been pretty bad. The reunion actually reinforced my appreciation for my adoptive parents and the home I was raised in. I'm sure visiting their mom gave them a glimpse of what life could have been like. Probably what you saw was their relief that they live with you instead.