Non-infertility-related advice sought

Should there be a different standard for acceptable behavior for family members than there is for friends?

My parents divorced when I was 9, and my father raised my sister and me. My mother visited us regularly but was never like a "real" mother to us. Among other things, my mother is not a truthful person, and she often broke promises to us when we were kids.

After having had a strained relationship with my mother for several years, we had grown into what I considered a good adult friendship.  In many ways, I don't look at her as a "mother," in the sense that I think of that word as meaning someone loving and nurturing who puts her child's interests before her own.  (My paternal grandmother filled that role for me when I was a child.)  But up until a couple of days ago, I thought of her as a friend, or the way you might your quirky-but-lovable, never-married aunt. . . . someone who shares your genetics and has been in your life a long time.

However, now something has happened which makes me wonder if I should continue any relationship with her at all.  She has been staying at our house for the past seven weeks, and two nights ago I caught her in a lie about something relatively trivial that happened in the house while I was at work. (So dumb: she left juice and chocolate milk where the dogs could get to it, after being warned repeatedly--and experiencing firsthand--that they can and will get into things left on the counter.  She tried to tell me the stains on the carpet were from dirt they had tracked in, when their true source was obvious, as the carpet was disclored purple and brown and wet down to the padding.  Plus, I found one of the dog-chewed plastic bottles in the trash.)

When I confronted her with her lie, she clung to it, to the point of being ridiculous because the truth was clear. She simply would not admit that she had lied to me.  She also later tacitly admitted to my husband that I what I knew to be the truth about the situation WAS the truth.

I got angry and told her that her lying to me was inexcusable and that I would not tolerate it (among other things), and I haven't spoken to her since. She was already planning to leave this morning (thank goodness) prior to our run-in.  At this point, I don't know when (or if) I will talk to, or see, her again.

If a friend who was a guest in my home had done something like this, the friendship would now be over. I simply would not tolerate having someone lie to my face, particularly in my own home.  Without honesty, how can there be any trust?  And without trust, there can be no true friendship.

 

Is there any reason why the outcome should be different because the "friend" happens to be the woman who gave birth to me?

 

Your thoughts?