When you (daddy) are out alone with your toddler Daughter, or (mummy) out alone with your toddler son, and needed to go toilet for the big one, (omg), what would you do?

I would suggest going into the handicapped toilet if available. Otherwise, can bring your toddler into the same cubicle in the gents/ladies. Better that than leaving him/her alone or with some strangers, will likely be more traumatizing than being in the same cubicle as daddy/mummy did his/her business (opps!).