The reason I don't let this bother me and the same reason dh's doesn't let it bother him is his aunt did the same thing! She has 3 daughters and a husband. Her older daughters are from one guy. The youngest is from another. She married her husband when her daughters were 16, 15 and 8 inthink. They are older now. It's like she hates on people just like her so she can feel better about herself.
Even though she goes out of her way to ignore dh and I, I realize she is just a sad and miserable woman who hasn't accepted her own mistakes.