And how do you prevent access for your next of kin if there is a breakup/fallout?

Important question - I hope OP can answer.

Too many people I know haven’t instructed their dependents how to access their crypto.

Just let them know where those details are and how to access them if they need to.

you can use multi sig wallets. Which are synonymous to Shamir’s Secret Sharing Algo; tldr you can generate say 5 keys and you need 3 of the 5 to unlock.

As for if you die … you could use one of those services that will send an email out to your significant others if you don’t log in for X amount of time.

> As for if you die … you could use one of those services that will send an email out to your significant others if you don’t log in for X amount of time.

And put your bitcoin private key in there? Surely whoever runs those services would take all your money.

If you use multiple services each with a piece of Shamir’s secret you are more protected. You can get more sophisticated with this if you want e.g each piece can be xored or encrypted with a value only that person would know e.g their birthday or their fav food.

Being your own secure bank isn’t a trivial task. Hopefully this can get easier in the future