Morally they would be subject to censure
Socially they would be subject to ostracism and ridicule. They would
lack certain hospital visitation rights, inheritance rights, tax benefits.
Politically they would be subject to prosecution (in the us in states
with anti sodomy laws) and would be denied the prosecutions afforded
by legal marriage.
The question: why and where are gender differences relevant?
Corvino's answer: gender is irrelevant to the moral character of
romantic and sexual relationships, and thus to other rights and duties
associated with such relationships.
Biological sex male and female, in terms of chromosomal structures,
XY and XX
Gender men and women, defined by a cluster of family resemblance
being biologically male or female
having or wanting to have a certain kind of body structure
having or wantin