Q: My son and his wife of 10 years divorced two years ago. His ex-wife had three sons from a previous relationship, now well into adulthood and going to college. When they were married we considered her sons to be our grandsons. We celebrated Christmas and birthdays together and have always offered them the same presents as our biological grandchildren. On a regular basis, I send them presents, even checks for tuition, but I haven't heard from any of them in over a year. They cash the checks, but no thank you, no phone calls, nothing. It's hurtful because we were quite sincere in our affection for them. Do we continue to treat them as grandchildren? What's good ex-etiquette?