My husband's adult daughter askes him to keep secrets from me

Maybe she knows you think that a marriage proposal is insignificant, and really doesn't want you involved. I don't know, but is it possible that you tend to be negative or dismissive toward your husbands children and their family events?

I agree with your husband. What his 30 year old daughter says to him is not your business.

I would agree the opposite way too... what friends or family say to you in confidence aren't any of your husband's concern.

Apparently he wasn't so compelled that he kept it from you . . .

If it is irrelevant gossip or insignificant then why do you care?

If you are concerned he is keeping something significant from you - why don't you ask him. Be direct and say I am concerned that you may keep a significant issue that would impact us/me from me - is this true? I understand that you may have some irrelevant family items that your children want to be kept from me, but please include me on anything that would be relevant.

Now just keep in mind he might take offensive if he has never kept anything from you - in other words he might take this as you do not trust him or his judgement on keeping items from you.

On the flip side I do agree with others a proposal is not an insignificant thing. Think of it this way - was it insignificant when you were proposed to by your now husband? Like others said maybe this is why these items were not shared with you - because you consider them insignificant when to all else it is huge.

Also - I don't consider keeping a secret away from someone else a big deal especially those that you will eventually find out about. Like an engagement - do you tend to be the type that lets things slip out therefore possibly causing the surprise not to be a surprise?

After the proposal, he told me that was the secret

Thank you