Seriously .. I need your advice?

Congratulations on finding a considerate employer! The breath issue with your colleague is a delicate one. Sounds awful. You could tactfully offer him a breath mint and take one yourself. Or you could politely say to him in private his breath is a bit stale and asking if he would mind taking a breath mint, or brushing after eating using baking soda on the brush along with the tooth paste, or by using traditional Listerine, TheraBreath, or some other mouth rinse specifically designed for serious problem breath. It is hard to say such things but you can do it politely in a matter of fact way, perhaps relating it to personal experience. You will be doing him a huge favor. Horrendous breath will hurt him in the business world. And by the way..... very bad breath frequently indicates a health problem: can be teeth, throat, stomach, intestines, etc. He may not know his breath is bad. Please find a low key way to clue him in. I once had a patient with horrible body odor. The rest of the practitioners in the clinic were making rude comments behind his back... not very well concealed. I invited him into a private meeting room and said something like, "I'm wondering if there is a specific health issue as I happened to notice a perspiration odor the other day." Something like that. It was very difficult to do. I was scared to death I would offend him. What happened was he was extremely grateful I opened a discussion. He was aware that others were ridiculing him and holding their noses even though they thought he did not know. He said it was a medical problem that happened no matter how many times he showered and made him want to stay home all the time. We were able to outline some ways to talk to his MD and dentist to get answers. You have to be careful how you bring it up and let him safe face, but you can really help him in his career if you help him begin to tackle this problem.