My teens got a text about an hour ago saying that their dad is marrying next weekend and they were welcome to come if they fancied 


The kids have taken my advice not to reply until tomorrow because they are furious at the short notice- they had no clue that they were engaged. Ds sees his dad EOW (came back at lunchtime) and had no clue until the text.
I know this isn't AIBU but am I being reasonable to be annoyed on their behalf? If I was remarrying, my kids would know as soon as they got engaged and would have roles like Best Man/Bridesmaid.
Older dd could have attended if she'd had enough notice (she works weekends) but swapped days and had this weekend off and is working both days next weekend.
Ex hasn't contacted me but I'm gobsmacked he would do this to our kids. They are furious being treated like an afterthought