Men and women who are single have dating rules they follow, and it is not surprising that the rules vary according to gender. Men are much more adventurous, but women tend to stay in groups. The rule for single women is that they go out in a group, and everyone must go home at the same time. If a woman chooses to meet a man after the group has broken up for the evening that is okay, but she cannot leave her friends in the chosen social setting.
Men's rules do reflect their nature, and it is not uncommon for men to go out alone. While single women generally go to social events in a group, men may be alone, have a buddy with them, or they might be in a large group. It does not matter if they leave the group during the evening, and some of them have signals worked out in advance to let their friends know they are leaving early.