Navigating a marriage I don't care about

So one of our alters went and got married. Great. Happy for them, but I don't care. Honestly I just feel kind of empty all the time and usually prefer to be alone. I'm really good at masking though and our husband doesn't know that I don't actually have any feelings toward him. I feel like it would hurt him a lot to find out even though he knows about our disorder and is pretty good with handling other aspects.

I just don't know how or if I should tell him. I do feel a bit guilty hiding this fact. I also feel guilty for not loving/being in love with him because of everything he has done for the system.

It's not that I would betray him or the other alters. I honestly have no interest in dating but I feel like I'm inhibiting my own growth and development by pretending to care deeply for someone that I have no emotional attachement to.