Relative obsesses over parentage of husband’s child

Dear Abby: I am married to a wonderful man who has a teenage son, “Teddy,” from a previous relationship. I have no children of my own. I love them both and have no resentments about or issues with having stepped into the role of stepparent.

My issue is one of my relatives. This person will not stop questioning Teddy’s legitimacy. There was infidelity in the prior relationship, and a DNA test was never done. While it’s true the boy looks mostly like his mother, everyone else can see his resemblance to my husband — except this relative. They constantly harp on how they “just don’t see it,” how Teddy actually looks like a mutual friend, and that I should demand a DNA test or do one on the sly.

I have tried repeatedly to gently and firmly shut this down by stating that I do see the resemblance and that a DNA test at this point would be pointless because Teddy has been his son for over a decade and it will never change, but they still will not stop. I feel like they somehow think they are “helping” by attempting to relieve us of parental duties, but I SIGNED UP to be a stepmother.

I don’t know what this person is thinking or how to get through to them that this is extremely hurtful and damaging and needs to stop. They are starting to be less subtle about it and will say these things when my husband and stepson are in the next room. Help!

Dear Stepmom: Gladly! Warn this toxic relative that if they mention this subject again, they will no longer be welcome in your home. And if the person persists in trying to cause doubt and pain, I URGE you to follow through!