NOBODY!
Even im a married person on which i cant really still that trust up my seed phrase into my wife. Yes, i dont have any plans on having divorce or trying to solo these money on which everything is really that being done for the sake of family and giving them a good life. I cant really just that make myself that trusting up that much on which it comes into a point that i would really be that trusting up my seed on which we do know that temptations is really that could happen specially if the amount will really be that significant. I do trust up my wife but there are really things on which are meant to be hidden or shouldnt really be that told. So far i dont have any problems on keeping away my seed as long it is really that out from other peoples awareness then it should really be just that fine. We do know that how important these seed phrase would be and its always been best that you should really be that wary and giving out that outmost security because once it will really be that someones awareness then there's always that tendency that you would be having that risks on losing those precious coins of yours that you've been holding for so long.
For many, it is complex to distinguish the role of a mother and a wife, which are the most important people around us when it comes to entrusting funds especially as a family man. For me, it is easy because I have looked at all options and possibilities and come to the conclusion that in the event that I have one person to entrust my seed phrase to, it will undoubtedly be my mom. Again, my choice may not be the choice of others plus I'm not currently married so I am not sure of the character of the woman I will eventually get married to.
As of now, I will entrust my seed phrase to my mom, of course I'm not also going to say NOBODY, like mentioned above because I don't want to die leaving my wealth to myself. So, that's not even an option. I must have one person to entrust my seed phrase with, and that's my mom. I will equally seek my mom to immediately release the seed phrase to my wife once I'm no longer alive, so she can use it to take care of my family.
I don't even necessarily need to tell her the full information about the seed phrase but I will let her know it contains my financial records or resources and should be passed to my wife almost immediately after my demise. I will also let her know it is an asset for my family being entrusted to her. This will be a secret I will leave between me and her and not even my wife will be privy of that information, ab initio.
I do also agree into your sentiment that since you arent that still married which is also im not married then i wont really be that trying out to do all the things to be in secret because it will really be such a waste if those funds or money will really be that lost into the void forever once you die or pass away. If you are still single then your MOM will really be your best bet and if you are married then it will be that in torn between your WIFE or your MOM but i do really love the idea that you would be sticking into your MOM on which that even marriage doesnt really give out any assurance that you would really be ending up on having a happy marriage life. There's no such thing about guarantee on which divorce is possible and same goes on having that death on which you do need someone that will really be able to give out those assets or coins once you do pass away.
So here's the cons of this one, what you would do if your mom passed away on which you have entrusted her just in case you do pass away too? We do know that it will really be that too unlikely that someone will really be able to die ahead of her own mom on which most likely they are the ones who do go first before us. Life cant just be predicted and its better to be safe than sorry. I do agree into those words or having some valid points on what milewilda said above that there's should be no one will be get entrusted with those phrases or keys but since the risks of losing all of those coins and someone doesnt know on how to access it out then those would really be that included into those lost coins in the void forever. If you dont like on having that situation then its better to let someone do know about your phrase but on the manner or sense that it isnt that complete or there are some missing words or keys and the other part should be entrusted into other people you do know because one of the main hesitance for most people that of those misused of funds or getting stolen once there's someone who do have access into your phrases.