Artem Chigvintsev and Nikki Bella's divorce is already getting ugly ... because they are at odds over two major issues ... money and their son.
According to a report by Us Weekly, Artem responded Friday to Nikki's divorce filing ... and he's asking for joint legal and physical custody of their 4-year-old son, Matteo.
The "Dancing With The Stars" pro is also asking for spousal support from Nikki.