How do you support your husbands/S.O. crossdressing while also staying true to yourself?

Can I advise from a gender dysphoric's point of view? Many dress out of wanting to feel normal, whether from stress or feelings of femininity. Yes, to many it's a sexual fetish, but to others they're items of clothing that represent who they wish they were born as. If you accept his doing so and support him dresseng, then you will have the most loving supporting partner that will walk to the ends of the earth for you.