See the double standards? It's acceptable and even 'cute' if a woman enters the male toilet due to accident or emergency/convenience, but reverse the genders and see what happens? The outcry and cries of "Arrest this pervert!" will echo throughout the building.
Women, it is YOUR problem that you can't use the urinal for peeing. It is YOUR problem that you take your bloody sweet time in the toilet (lengthy phone conversations, applying makeup, changing pads during that time of the month, chatting merrily with your BFFs or co-workers), hence causing a long queue outside a female toilet during peak hours.
Don't impose your biological dysfunction and inconvenience on men. Either shut up and queue up, or find another less crowded female toilet. The only time when you should enter a male toilet is when you're going to get fucked in the cubicle by a man. Otherwise, go away.