Thinking about the ginger curse in @quesocheeso's aus
Particularly in the genetic context and if the genes work like they do in cats so for the sake of this argument/shit post, let's be silly and say they do because we already make the monkeys purr like cats making the genes work the same isn't that much of a stretch.
So, the orange (ginger, it causes the same pigment so I am going to use them interchangeably lol) color gene is located in the X chromosome.
For male cats, they only have 1 X chromosome so they only need one copy of the gene which is why orange male cats are more common than orange female cats since orange female cats either need both parents to be orange, or an orange father and a mother who carries the orange gene.
Wukong is your standard orange cat, 1 x chromosome with the orange gene that he expresses visually and since MK isn't also orange and the only difference there is that it's Nuwa x Rock Mom instead of Rock Mom x universe, we assume the universe is a ginger too and that's where it came from.
Orange male cats aren't passing their orange genes down to their sons, they only pass it down to their daughters since they pass the colorless lame-o Y chromosome to their sons and make them, you know, male.
Following this highly scientific logic, Xiaoxing and Xiaolei aren't getting the ginger gene from Wukong, he's passing down the Y chromosome, they're getting it from Macaque.
He's got super secret sleeper agent ginger genes!
He's being betrayed by himself passing down his own ginger gene each time.
The only one of the three kids getting the orange gene from Wukong is Xiaoyue since she needs it from both of them to show it.
However, it is also entirely plausible for them to also have the equivalent of a tortoiseshell baby since Macaque has the black fur gene (Idgaf if it was white originally in this argument, it'll be black eventually) and Wukong has the orange fur gene they could totally have a tortoiseshell daughter!
Because lil fun fact, every tortoiseshell or calico cat you see is almost guaranteed to be a female. The cat needs 2 X chromosomes to show black and orange coloring. If it male and tortoiseshell/calico, it's an intersec XXY cat :3
If they had a tortie baby she'd have so much tortitude
Thank you for coming to my Ted talk/crappy genetics rant
I recently got an orange girl kitty and have a tortie kitty so I been thinking about these genetics a lot and naturally it went to the monkeys lol