I have never committed on anyone that I have been committed to. If I am "involved" with only one person, then there is only one person.
Always love your posts! Oh, and aswering the OP's question: absolutely not! I only get into a relationship when I'm REALLY into the man in question. If at some time he starts messing up and treating me badly I'll just dump him. No need to cheat when I would hate to be cheated on.