my twins are her half siblings .
Dh is furious/hurt and upset that hes to go to the wedding " with his ex " and is not able to bring me, his wife.
He is also upset that all the children cant go . (we look on all 8 kids as "ours ", it doesnt matter who their parents are , or how they came to be in our family , its the fact that they are our family that matters iykwim. 3 from dh and ex-w , 3 from me and ex-h , and the twins together).
Thing that gets me , is dd1's fiancee has invited his step-dad and all of his half siblings.
I think dd1's real mum and auntie have had an influence. The auntie will be there too .
I told dh last night , that he shouldnt fall out with dd1 over this , as she is his only daughter who will get married (dd4 has autism & severe learning disability, so is unlikely to ever get married) , he would be throwing away his only chance of walking a daughter down the aisle.
DH's great revelation last night , was after she told him i and her twin siblings were not to go to wedding , she asked him for the money for her wedding dress. 
Im still pretty much gutted by this , but after a good nights sleep , its a bit more in perspective.
I dont really want to be in a room with dh's ex for any lenghth of time.
Its like im getting punished for marrying dh (at times).They split long before i was with dh , but i get treated like a home-wreaker. All i ever did was try to be supportive to dh's relationship with his children , and an extra help to their mother.
I give up.
Next time she phones wanting a lift or cash , she'll be told to jog on.
Ironicaly dd1 was main bridesmaid at mine and dh's wedding.