I'm assuming you are talking about M.W. If that's the case then yep, you should have said something (especially to her) since this always seems to be a problem area. Next time, make it clear and be direct. As a parent, I would rather know up front if I need a sitter or not. And there is NOTHING wrong with wanting a kid-free evening.
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Life is Short...Run Long
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Life is Short...Run Long