Should teenage girl break up with boyfriend just because he smokes cigarettes?

No. If the girl cares about him/really likes or even loves him, she should accept all aspects of him, good and bad. Besides, there tends to be more good qualities to a person than bad, and if she's willing to overlook the good qualities and focus on the bad she shouldn't be in a relationship with someone until she learns how to do that. However, it's entirely up to the girl to decide, not someone on WikiAnswers.