PA or DC State of Domicile

If you move from Pennsylvania to Washington DC (staying with someone) to be closer to work (Virginia) but you don't plan to live there longer than 2 yrs, which state would be considered your state of domicile?

 

Which tax form do you file with your employer? Documentation like Driver license, vehicle registration, voting registration is all in Pennsylvania.

 

Residency vs Domicile?

 

Thank you!