Dear Amy: My lady friend, “Kate,” and I have been together for nine years. We both have children and grandkids from our marriages. We are active seniors and travel often. When not traveling, we go out to dinner several times weekly, and are fairly active socially. When my grandkids came along, I made it perfectly clear that I would be more than willing to babysit now and then — whether it is for their parents to have a date night, or if an issue arose where they couldn’t find a sitter otherwise. I said I would not be a built-in sitter; I would not commit to sitting every week on a set schedule.