How / when to tell people who aren't invited?

[MafaldaGregorovitch]

Small wedding, less than 15 guests invited. How / when did you tell people who aren't invited? Especially as there are a couple we'd know that will be offended / upset about not being invited.

My cousin who I am very close to didn't invite me to her wedding. She had her mum her 2 sisters and his brother there. I was gutted. (At the time I spent hours listening to her go on about all the issues between her sisters etc). I'm still upset years later.....but I also know why she kept it small and am not falling out with her over it. But just don't minimise friends and families upset and disappointment.