The way I see it, opens relationships get a bad rap thanks in part to a misunderstanding. An open relationship is not an excuse for a partner to lie and cheat. It is a way for two or more people to figure out a relationship dynamic that works best for them.
Open relationships are non-monogamous, which can mean any number of things. For some, this means being in a committed relationship but taking on different sexual partners. For others, like Ronaldinho, it means three people wanting to be in one relationship. No matter the interpretation, ideally trust and open communication are always at the forefront of these types of relationships.