It does in some areas though. E.g. you have provisions like this one from the housing act, talking about when tenancies can be automatically transferred, on the death of one spouse, to the other one:
"a person who was living with the tenant as his or her wife or husband shall be treated as the tenant’s spouse, and a person who was living with the tenant as if they were civil partners shall be treated as the tenant's civil partner"
(Interestingly, an identical provision in another act - but with only the wife/husband language, as this was before civil partnerships - was used by the courts to give a similar benefit to a surviving member of a gay couple, using the non-discrimination provisions of the Human Rights Act to interpret the provision broadly to include gay couples living as partners (Ghaidan v Godin-Mendoza)).
