All the time you are on SS or 790 you will be in a mild state of ketosis and hence can have bad breath as the ketones get emitted.
To try and stop this do the following!!
1. Drink water, the more you pee the ketones out the less you breathe them out.
2. Clean your teeth
3. Use mouthwash
4. Get a Gold Spot spray and use that just before those "close" moments i.e. 1 to 1 meetings etc.
5. Drink black coffee or tea as these also help with stopping the smell (especially coffee as you smell of that instead!)
Failing all that get your boyfriend on the diet and then he'll be in ketosis so he'll think it is him.
Mike