Fun Fact(s)!
1.) Goblins and Orcs both have completely normalized the existence of trans and intersex people. Its always been a Thing, and both societies readily permit queer marriages.
2.) Goblins, Orcs, Giants, Dwarves, and many human societies used to practice Marriage By Conquest, aka forcibly taking vanquished foes or citizens as spouses (sex slaves/hostages). While the majority of Azo societies have abolished this, some communities are clinging to it. Some Orc communities deliberately seek out human fiefdoms that permit the practice and then limit their nomadic territory to within those borders and a few goblin nations still recognize Conquest Marriages as valid and will refuse to return the spouse in question to their homeland.
3.) Most mortal species can produce children together, and their kids have a fairly even mix of their parents' species traits. This has been happening since before the first cities were built, nobody really gives a fuck.
4.) Orcs didn't used to have any concept of marriage. They adopted Marriage By Conquest from Goblins and Giants as a means of specifying valuable, foreign-born concubines, and gradually amended the practice into a way of granting a newcomer permanent membership in the war-band
5.) Dwarves likely invented the entire concept of marriage among mortal species. Basing it off the Lover's Pledge taken by certain pairs of the Gods, they conceived of marriage as a special type of contract between two families in which inheritance rights and property claims were traded as part of the deal. Dwarves are known for a fact to have created the concepts of divorce, pre-nups, annulments, and alimony.
6.) Giants are believed to the originators of Marriage By Conquest, as there ancient records of giant soldiers claiming enemy troops as concubines during The War Age. Other sources indicate that it was the Gods who originated the concept: Rayic and Tara both took sex slaves as prizes during the War Age.
7.) Goblins have dozens of words for "marriage" aka "a legal and social contract in which two or more parties bind themselves together to some degree". They have words specifying MBC, political marriage, economic marriage, love match, something translating as 'practical marriage', and several other culturally specific ones. Unlike most other mortal societies, goblins allow plural marriages. Love matches have been common among goblins for most of their history, even among their nobility and aristocracy.