Would you consider having an open relationship, where you can see other people?

I think what makes me laugh the most about North American culture when it comes to relationships, is that single people who are on the dating scene will behave as if they're married to the 'one' they've been seeing, especially if that relationship has lasted more than two weeks, simply because they tend to apply the mentality of 'marital ownership' of the other person if they have that much time invested in them!