Common potential in Capacitors

If two isolated charged capacitors (of different capacitance) are connected in parallel to each other they acquire a common potential. But suppose if i connect positive plate of one capacitor to negative plate of another capacitor will they still acquire a common potential or will the charge acquired by two capacitors be same as the circuit looks like that the capacitors are connected in series in which -ve plate of capacitors is connected to + ve plate of another capacitors