Telling someone that they have bad breath can be a sensitive topic. Here are some tactful ways to approach the issue:
Offer a mint casually: The simplest way might be to just offer a mint or gum casually. You could say something like, "I'm having a mint. Would you like one too?"
Empathize and share: You could say, "You know, sometimes I worry about my own breath, especially after certain meals, so I always carry mints/gum with me. Would you like one?"
Direct Approach: If you feel comfortable enough, you could address the issue more directly but gently: "I hope you don't mind me saying, but I think a mint would make our kissing even better."
Suggestive approach: You could playfully suggest, "Let's both have a mint before our next kiss."
Turning into a habit: You could also turn this into a shared habit. Say something like, "I read that having a mint or brushing our teeth before kissing can make it even more enjoyable. Want to try?"
Remember, the goal is to not make her feel self-conscious or embarrassed. Consider the approach that best suits your relationship dynamic and her personality. It's always best to approach such topics with empathy and kindness.