I feel the same way... I always find it weird when I see a group of women with just the 1 guy with them?
Also this behavior goes on with men also. Especially with men who are no longer with their children's Mother's. Guy's feel as though they have some territorial right because they had a kid together.
Not all men do this just as you are talking about a certain type of woman, I am speaking about a certain type of Male...
Fun read