TK - I think I get your issue. We had many, many issues with my MIL after DD was born (soooo hearing you on the 'not holding the baby' - in our case not long enough - kind of whinge). Her retaliation was to shoot off a four page email of abuse and insults (mostly directed at me, even though the argument responsible for her meltdown was with DP) saying she would be putting money away for DD and keeping a journal so DD would know how horrible we were to her when she was old enough. Real mature, huh? She kept it up for six (blissfully quiet and peaceful) months where she didn't contact us, until she decided that wasn't working for her and got back in touch. The saga continues, but enough about me...
I know she has an account that she says is for DD, but I couldn't give a toss. If she dies before DD is old enough, we'll be responsible for the money as her legal guardians anyway. If it's in trust, then DD can access it once she's 18. We haven't discussed it with MIL since it doesn't affect DD now or any of our decisions in relation to our dealings with MIL and her relationship with MIL. So I don't see an issue with a grandparent opening an account to put money in for a grandchild per se. TBH if MIL dies then DD probably is a beneficiary in her will anyway. (Especially if she stuck to her threat to cut DP out :rolleyes:.)
In our case, MIL is definitely doing it to 'big note' herself (thanks, Leasha, spot on description) and prove that she's the world's best grandmother. I'm not sure who she's trying to prove it to, but it's clear some of her friends have gotten the message, based on comments I've overheard. DP and I are of a slightly different opinion and you'd think it would be our opinions that counted more, but there you go. And DD is too young to have much insight into things, other than Grandma comes over and plays with her. I sincerely hope DD's relationship with her grandmother is actually more harmonious than the relationships that MIL has had with every other person in her life, but I seriously doubt it will be. I'll just have to help DD deal with the fallout (which will hopefully be contained given the close supervision we provide).
It sounds to me that your DP taking his parents' side is a big issue. You are going to come up against many, many different things that as parents you will be challenged over. Particularly with ILs who like to have a stake in things and don't keep their opinions to themselves. The discussion about whether or not ILs should open a bank account for your DD should have been conducted by you and DP, behind closed doors, and then a decision made and given to them. If they think they can have input into your parenting decisions, I see a world of pain.
Your DP needs to realise that you and DD are his family now. Regardless of whether or not the bank account should/shouldn't be opened, he should have talked to you about it first and then gone back to his parents. If you both disagree, you'll have to sort it out between you. Compromise. DP and I have had many, many arguments over dealing with his family, but at the end of the day, my ILs have only ever seen the two of us in agreement when it comes to dealings with them. I might not always like the song, but I sing from the same song sheet. And if it's DP's family, well, he has slightly more influence on the decision than I, just as I have a bigger say with my family.
As for "I'll leave you" threats - it sounds like he doesn't have a very good reason to not support you so is resorting to emotional manipulation. My DP has done this in the past too. Ignore it. If he wants to leave, he can leave. Don't allow this line to change the fact that the two of you should be deciding on this together. Backing his parents over his partner is a BIG NO NO! Tell him so and try to sort it out. :hug: I'm sure you guys have worked through plenty of issues in the past 10 years, you can do it here to.

