Original sentence: It is also called same-gender marriage, gay marriage (both of which are problematic labels), marriage equality - often just marriage by its proponents, and - usually by its opponents — homosexual marriage (which label has the same problem as "gay marriage")
Edited sentence: It is also called same-gender marriage, gay marriage (both of which are problematic labels), marriage equality - often just marriage by its proponents, and - usually by its opponents — sodomy marriage or homosexual marriage (which label has the same problem as "gay marriage")