Something I'm really appreciating about the Moon Knight show is they're doing a large plot beat about the betrayal Layla feels about Marc keeping the system from her, while doing a lot of work to keep it more nuanced than just "how dare my husband not disclose his highly stigmatized mental disorder to me".
Layla does not give a shit that Marc is part of a system! After meeting Steven and putting the pieces together, one of the first things she does after seeing Marc is show him that it doesn't bother her, to offer acceptance and show him that she isn't scared of him. That she still loves him.
But on the flip side, Marc was very seriously hurting these past few months, and didn't let her know about any of it. She's allowed to be upset about that, to feel betrayed that he was keeping a massive part of his life hidden from her out of a martyristic urge to "keep her out of it". And he does this with way more than his DID too! Her father's death! Khonshu's threats against her! His own lowkey suicidal ideation!
The Steven thing gets restructured to be a certain kind of cutting because after she spends some time with him it's glaringly obvious that they get along very well and have a lot of mutual interests. While a lot of Marc's other lies are self sacrificial bullshit, they are, at least, all about bad things that he doesn't want people to know about because he thinks it will upset or endanger them. Steven is an objectively good thing that makes Layla's life brighter, so on top of Marc's already shitty ways he has tried to keep Layla from being able to make her own choices, it goes to show how flawed his judgement really is.
They make it a recurring character flaw of Marc's that he simply will not share information even under the most extreme of duress, and how that absolutely blows up all his relationships in his face every time because he tries to make decisions for people he cares about without any input from them. And Layla is allowed to be upset about it!
And at the same time, they are still two people who care about each other very much, and their DID is never presented as an obstacle to their relationship, nor something that Layla sees her husband as any lesser for living with.