Well then I must not be at the twins, I didn't see a "take cover" like last time so I assumed my only option was to attack. To be clear the spot I was referring to was directly after pitri "dies".
After Priti gets shot you come up against April and Alice. Take cover then and you'll end up sneaking around the side and encountering Cassandra. Get past her and then you come up against the twins. You'll always get shot the first time you fight the twins. After you get to them though a new water pistol will unlock in the online store (under electronics).