If I don’t accept a plea bargain will the prosecutor raise the plea?

If I don’t accept a plea bargain will the prosecutor raise the plea?
My fiance is accused of 1st degree burglary and 3rd degree assault. His brother has already plead guilt to these charges. The prosecutor offered my fiance a plea of 120 days in prison for the burglary charge and to dismiss the assault charge, which he did not accept.

Justin’s Answer
Given that the prosecutor does not usually offer plea deals to un-represented defendants, I’m guessing your husband already has an attorney. This would be a better question for that attorney.