You can kind of do this already with 1 of your friends. Here is a rough idea of how you would do it:
  • Have your friend send you their multsig xpub and derivation path for their signing device.
  • Create a 2/3 multisig and use their xpub + derivation path as one of the sigs in the multisig.
Your friend wouldn't be able to see your wallet since they don't have the other 2 xpubs + derivation paths, but if they needed to sign a tx they could.
Downside to this is your wife would need 1 of the sigs to get your Bitcoin. You could do a 2/3 and have your friend and brother be signers but they technically could get together and steal your Bitcoin.