Bad Breath and Yellowish Teeth: Yellowish teeth and bad breath will never attract the opposite s*x.
Think of the reason what causes the problem. Are you a smoker? Or is it just your poor hygiene? Maybe you drink too much coffee, black tea, or red wine?
In either case, do your best to solve the problem as soon as possible. Use whitening toothpaste or strips to make your smile brighter and carry breath dragees in your handbag.