The interesting thing about computer games is that it actually takes MORE code and makes the game MORE complicated to insist on male/female only marriages.
I remember back in the day that Sims got in some hot water over that because they just had an "attraction" setup based on character attributes but sex was not one of them. They ended up having to add a brute force no same sex code to the game after launch because of the outrage over that.
From a computer programmer point of view, I found that to be highly amusing.
My dear old mother was not nearly so amused about the fact that I found that amusing.
