Ain't no way they're mad that op didn't tell them that the event was a wedding when she did and got ignored and also they decided not to come so its their fault. NTA

Publicly post the threatening texts, as well as the invites sent to them which they ignored. Who'd defend those abusers then?

It's not on OP to chase down her parents and force them to be adults. She sent the invites, and they never responded. That's on THEM. Actions, meet consequences. NOW the dad is upset because he missed his only daughter's wedding and the chance to walk her down the aisle. Too bad it's too little too late. This really hurt to hear/read but I'm glad OP has grandpa in her corner.

I would go NC with the whole maternal side

She repeated.stated that her event was "perfect" without them there..that in and of itself is enough. If something is better is better to the point that you'd describe is as perfect wothout someone or a group, that is all you need to know going forward about where those people should stand in your life moving forward. If havung these people around dyring meaniful points in ykur life makes those points worse than those people have no right to be there for them, and nobody attempting to force their involvement third party or otherwise needs to be given any explanation or consideration.

Any claim by anyone that OP was in the wrong can be met by “they got invitations and ignited them, I followed up on them and they ignored it”

How do you miss a wedding invitation? I can always tell a wedding invitation or graduation announcement because they're really fat, heavy letters.

Op did more in fairness than many people. I believe many people wouldn't have even bothered to send invites, after the gaslighting they gave Op.

I saw a similar one where the bride posted picture of wedding and one with MIL captioning thank you for being the mother I never had

NTA

OP sent them invites, tried talking about it with them, sent reminding text messages, openly discussed the wedding in front of her mom, and her parents and brother are claiming they didn’t know? The only reason they would not know is if they automatically ignore anything sent to them by OP and don’t even look at it. I 100% guarantee the wedding invite was never opened, they just saw it was from OP and trashed it or put it in the same place they keep random unimportant mail that never gets dealt with.

*reads title* how the fuck do people just not know if or why they are/aren't the asshole. Sure you do get the occasional YATA but most of these are definitely not asshole like at all, I'm not even sure I need the context to know that op is not the asshole, they'd have to have deliberately not told their parents (or concealed it) that op is having a wedding to be the asshole. Absolutely baffling that people need an outside opinion just to know they are not wrong