Mary,
I have thought about your situation a lot this morning. At first I thought it was a bit rude of them to choose this particular day to want to spend time with their father but now I think I feel rather differently.
I think you should spend some time with your sons (after all you aren't your husband's mother!) and enjoy remembering some of your happy times that were special to your little family.
Meanwhile, your husband's daughters can enjoy remembering their mother, they can talk openly and freely about her to your husband (without any of them perhaps feeling disloyal to you).
Whilst it may feel to you that they can talk about her in front of you, not everyone will feel like that. My mother-in-law for example has only recently started talking openly and often about my husband's father (who died when my husband was a boy). She had been waiting till after her second husband died. She had remarried, and told me recently it felt disloyal to talk about her first husband "more than was necessary". My husband therefore hardly got to speak about his father for years which was quite a sadness - but if his mother had died before his stepfather he would never have had the conversations he can have now.
Please try to be pleased that once or twice a year your husband and his daughters get to spend this time together. It is a great gift you are giving them. You are not in competition with their mother, you are generously acknowledging the happy times they had "before you".
So why is this happening now? Maybe because they are roughly the age she died? Maybe because as adults we are more curious about our history and families, maybe because they know your husband is getting older and they feel the need to cement memories and understand more deeply about their mother. At 16 and 19 they would have had a very different understanding of their mother than they will do as grown women (maybe with family of their own?).
Maybe they are using the modern phrase "to make memories" instead of saying "to spend time remembering" out of respect for you.
Whatever the reason, let it go. You are fortunate in that you have enjoyed your marriage for many years and as others have said, you have their father to yourself most days. They have no mother to celebrate on Mothering Sunday and that is a loss that all of us without a mother can understand. I wonder what your stepdaughter have done on Mothering Sundays past?
I do hope you have a lovely day with one or both of your sons and I'm sure you will have many other happy days with your family (extended or otherwise) as the years go by.
Please don't be sad about this. I hope you have a memorable and happy day. ?
Ethical question - how do you feel about second chance??


