Unless you feel in danger or you can't afford to, stay where you are. You also shouldn't file for D first if you don't want the D.
Let her know she's welcome to take any and all steps she feels are necessary, but if this is what SHE wants, then SHE has to make the moves.
ME: 38 BF: 40 T: 10y, no kids, no M (by choice) BD: 7/14/14, BF admits to PA, wants out, lies about new R. 10/1/14: I move out, BF lies about move in with OW 12/4/14: OW confronted, reveals all the lies