Buy him mouthwash 😂 be playful while handing it! Laugh around while giving him it and be like ok dont be embarassed but i want u to use this diligently! Or if the convo is gonna be too painful for u, u can gift him a ‘set’ of cleaning stuff like soap along with the mouthwash. And he can find out y u gifted him it on his own. If hes smart he’d find out no?
Oh love I’m sorry. I honestly would address it head on. Something to the effect of “hey I have something I want to talk about. I have noticed something off about your breath. I’m worried something is wrong, are you okay?” Please word it nicer, but compassion and directness is key here.