I completely agree with this. I used to go to Church when I first moved into the place I live now (about 10 years ago,) and there was a big bunch of about 12 or 13 quite cliquey women there. Pleasant but very tight. There was one of them (Ann) that used to hang on to me like a limpet. She was so possessive and obsessive and constantly wanting to know everything about me and what I was doing and lots of personal intrusive questions about me ... She was so nosey. After a while - about 8-9 months I started giving her a wide berth.
She was actually one of the reasons I stopped going to church so much and cut it down from three to four times a month to once or twice a month. A new trainee minister came to the church; (he was actually learning the craft from the vicar there,) and was there twice a month. He was due to be another church a few miles down the road later on.
6 of these women in this group got invited to his wedding, because they were very thick with the vicar.. 'Ann' was not invited, but she pretty much invited herself. She said to the trainee minister. 'Oh yes, me and Steve will be able to come. That's so wonderful - we're looking forward to your wedding!' She actually invited herself! No-one had the nerve to say she can't go.
I was actually talking to the women in the group who were invited, and this weird obsessive woman (Ann) joined in the conversation, and she started going on about the wedding. 'And oh, I'm coming to your house first, aren't I? Annette. It'll be so much fun at the wedding. I can't wait. Can you Julie? Sarah. Linda, Liz?'
She kept blathering on about this wedding that I wasn't invited to. All of the women in the group who were chatting were going to it... Except me. After about 30 seconds of Ann talking about it, one of the ladies actually turned the subject off it - and she turned it right back on again.
I really, genuinely think it was to rub my nose in it that I wasn't invited, to be spiteful, because I had been giving her a wide berth. But I wasn't expecting to be invited because I didn't really know the couple that well. She was only going because she'd invited herself. She didn't know the couple any more than me! She only moved into this area 3 months before I did, and got herself in with the Church clique quite quick! I carried on going to Church for a while - a couple of years - but went less and less and less, then stopped altogether when Covid hit and never went back.
But yeah, tl;dr, it is beyond rude and spiteful and nasty, to chat about something that is going on - like a 'do' or a party or a wedding, especially with other people who are invited - in front of someone who isn't.