I have never been able to sleep around freely either. It's not for everyone. I don't shun someone because they have multiple bed partners. THe only time this is an issue is if the guy I am with is sleeping around with others when we are supposed to be in a monogomous relationship.
I can honestly count on one hand how many partners i have been intimate with at 32 years old. But that's me, and I don't impune anyone else for not being able to.