There's always the "third party" approach
If you want something then use a "third party" that has some perhaps more influence on Mrs's decisions that you do.
First, you have to know if the "third party" will be sympathetic to your cause
Second , engineer to have a coffee or dinner with "all parties" and bring the topic up in conversation. Seek approval from "third party" that what you want is a "Good Thing"
Third, go for the dummy close "yeah but I dunno of we can get that even if it's a good thing like you say..." Third party says, "I would if I needed it" (reasons etc given)
Fourth, time it right, go for the close, get agreement and then do the job!