As a SM put yourself in your DD SM's shoes and don't email him. He's dense and an idoit. He shouldn't have even said that to your DD knowing he knows the respectful thing to do which is just tell his wife and she might be okay with it instead he chose to throw SM under a bus. He should help your DD out, if he can, hell my dad called me out the blue a week ago to meet him to give me $350. Of course, I didn't keep declining it (his SD my SSisiter and SM has practically drained him) when he kept insisting because I never ask and take care of mine. But I bet a million bucks his wife probably didn't know but I have another level of respect because I know he didn't tell me not to tell his wife. He did say "I help her I can help all my girls you got 4 kids to her 1" but still..

I see it as he wanted to help his daughter out and maybe for whatever reason he didn't really have it to give but wanted to do it anyway.  Because of this for whatever reason he didn't want anyone to know,  his wife or maybe even you.  I don't know any of the history here but it was nice of him to put her needs ahead of whatever trouble it could cause in his life in doing so.

If a child isn't asking for money all the time and as long it is not a huge amount I don't think a spouse has to share that they gave their child some money.  These are just my thoughts.  It is also none of my business and I don't know your history but I am not sure why you care about why he asked her not to mention it.  I think you should just care that he helped her out and leave it at that.  

I think your DD might have shown more restraint.  I understand you are her mom and she feels close to you and likes to "share" with you, but she probably shouldn't have repeated what he said about his wife.  She could have simply told you her dad gave her some money to help her out.   As an adult, she should understand this.

I think it would be better all around if you told your DD not to share those kinds of details with you anymore.   "Honey, you know I don't have anything against your dad and I am glad you have a relationship with him.  But I really don't need to hear anything he has to say about his wife, so I'd rather you don't share that with me."

Apply the golden rule:  Would you want your DD to tell your ex things you said about your spouse/partner?  

This was an interesting post, especially considering the responses. I have to admit, my first thought when I read this was ‘the SM sounds like hard work’. Ugh. How’s that for programming for you...

This seems like a simple situation but there’s a lot happening here. You know your exh better than any of us, so if you say he’s being dramatic in telling your DD not to mention anything so his wife doesn’t get upset, I’ll take your word for it. Who’s to say that she’d get upset in the first place? And if she did, is it because he’s irresponsible with money? Do they not have an extra few hundred dollars to give to adult children? Or is she really just an unreasonable person? Who knows, all i know is my first instinct was to assume the SM was unreasonable, and that deserves to be challenged. 

I don’t think spouses should keep things from each other. I am not one who believes there is innocence in a lie of omission, and I say this with confidence because I’ve been hurt many, many times by lies of omission, and it hurts & breaks trust just as much as an outright lie does.

At the same time, I do think, if there is money available and no financial abuse happening, partners should be able to spend a certain amount without telling each other on whatever they want. The fact that your ex felt the need to lie leads me to believe that either he & his wife don’t have that agreement in place, he’s being dramatic & stirring up trouble needlessly, or his wife really is difficult and he feels the need to lie, which is it’s own issue & they need to work on their relationship instead of bringing your DD into it that way. 

This one really made me think!