The Sheriff's girl friend constantly asked the Sheriff to get married.

Girl: Please, marry me?
Sheriff: I can't. I have to go catch the bank robbers.

Girl: Please, marry me?
Sheriff: I can't. I have to go catch the rustlers.

Girl: Please, let's get married?
Sheriff: I can't I have to go catch those who held up the train.

Moral of the story: Some men would rather fight outlaws than in-laws!