However, excluding relationship by blood, your hetero spouse and gay/lesbian partner can also be your next of kin. Now here is where the UK fails in their "separate, but equal" rubbish.  Non married hetero couple that have lived together for 6 months or more are also considered next of kin.  The same rule DOES NOT apply to non civil partnershiped gay couples.

So someone tells you that gays have total equality in the UK, excluding the word "marriage" and all the international acceptance that word has, just remember this.  It's one of a number of things in the UK where we are still 2nd class citizens.